This resolves a TODO. Also, it allows go/types and types2 to use
identical test files in testdata/spec, a prerequisition for sharing
them eventually.

For #54511.

Change-Id: Ia9d11b15ada237c18b6ce8f72732f70134a1a06f
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Instead of simply reporting an error but otherwise dropping the
index expression from the parse tree when an index is missing
(as in: x[]), create an index expression with a "bad expression"
as index. This matches the behavior of go/parser and permits the
use of the same test case for both parsers.

(It would be simpler to adjust the go/parser to match the syntax
parser's behavior, but that would break backward-compatibility
of the go/parser.)

Adjust the affected test files.

For #54511.

Change-Id: If7668973794604593e869a24b560da92e100b812
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Besides applying gofmt (which doesn't damage the tests in this case),
the ERROR comments in the types2 files now match the go/types files.
But because types2 still reports some errors are different positions,
the checking code now allows for some position discrepancy (similar
to what we do for other tests).

Except for an outstanding TODO in go/types/testdata/examples/types.go
the test files are now identical.

For #54511.

Change-Id: I5748e0f678d11c5c0bdf4fdf28bd04f0b11b5b23
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Besides applying gofmt (which doesn't damage the tests in this case),
this removes a TODO for a set of nil-related tests.

The test files are now identical.

For #54511.

Change-Id: I0a286ad607f317f43972c1f5ee741b4f5bc9576d
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Since the spec tests are now identical between the two type checkers,
remove the local copy of the spec tests and (for now) use the tests
in go/types/testdata/spec instead. Eventually we may decide to move
all tests out of the type checker directories and place them in a
shared space (e.g. internal/types/testdata).

For #54511.

Change-Id: Ibc62230553a5ff215160dcc97696b333ae9cf685
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Follow-up on CL 424674. With this change, the files in
testdata/examples are identical to the corresponding
files for types2.

For #54511.

Change-Id: Ic61c089bbf61492094e31057ad2635803f50a30d
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Since the examples tests are now identical between the two type checkers,
remove the local copy of the examples tests and (for now) use the tests
in go/types/testdata/examples instead. Eventually we may decide to move
all tests out of the type checker directories and place them in a
shared space (e.g. internal/types/testdata).

For #54511.

Change-Id: Ibd8599d09e781b2219a23114b4b2049757971181
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For #54511.

Change-Id: I571680dfc25d7b7198e84e11bd311ab8b24d72d9
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The validity of an import path string is checked by the type checker
(and possibly other tools); it doesn't need to be done by the parser.
Remove the respective code and tests.

Also, adjust a corresponding go/types test which resolves a TODO.

For #54511.

Change-Id: Id1fc80df4e3e83be3ef123da3946ccb8f759779f
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Use same approach to parsing const and var declarations
as the syntax package. Specifically, don't complain if
the first const specification in a const declaration
doesn't have a type and initialization expression. This
removes some duplicate errors when combined with the
type checker.

Adjust corresponding type checker tests accordingly.

For #54511.

Change-Id: I96702eba51dda6b581dad44577a7f93e4c02c857
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Use "invalid" rather than "incomparable" in error message for map key
types that are not comparable. This is the original compiler error
message and many tests check for this specific message. The type
checker does provide an additional explanation if the reason for
the error is not obvious (e.g. for type parameters).

For #54511.

Change-Id: Idb76c48b4dfbfd66a7deac728a552e07f14e06d7
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Use "middle" and "final" rather than "2nd" and "3rd" in error messages
for invalid slice expressions. This is the original compiler error
message and many tests check for this specific message.

For #54511.

Change-Id: I86eb739aa7218b7f393fab1ab402732cb9e9a1f6
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Use "method has no receiver" and "method has multiple receivers"
in error messages for invalid receiver counts, matching the
corresponding types2 errors.

For #54511.

Change-Id: I96fc99440d6206c74e9416069db052234baa8248
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The change in typexpr.go matches types2 behavior.

For golang#54511.

Change-Id: I79c922a94f2ee0440c1814140935c321439c7d25
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This matches types2 behavior.

For golang#54511.

Change-Id: Iea906e9fec7e334b7aa7f481de87373fa93d1c7c
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CL 425716 changes parser behavior for incorrect code (it is more
lenient) which breaks a few lsp tests. Disable them for now so we
can submit CL 425716.

For golang/go#54511.
For golang/go#54822.

Change-Id: I00fa67e29628137f3e4e44c38e92094ea581a61b
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Remove the code that verifies that an expression is a type or non-type
expression. For one, it cannot be done perfectly accurate
(e.g., consider *p which could be an indirection or a pointer type),
it also unnecessarily slows down parsing. It's simpler to leave the
verification to the type checker which has all the information needed.

Remove short compiler tests that tested the expression/type property.
Adjust a couple of go/types tests which now trigger because the parser
doesn't complain anymore.

Change file for benchmark from "parser.go" to "../printer/nodes.go"
to avoid a moving target when benchmarking.

The parser may be marginally faster when tested on nodes.go:

name          old time/op    new time/op    delta
ParseOnly-12    1.35ms ± 0%    1.31ms ± 0%   ~     (p=0.100 n=3+3)

name          old speed      new speed      delta
ParseOnly-12  39.9MB/s ± 0%  41.0MB/s ± 0%   ~     (p=0.100 n=3+3)

For #54511.

Change-Id: I9a32c24c2c6e843c3d1af4587651c352f378b490
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…bad go/defer

If the go/defer syntax is bad, using a fake CallExpr may produce
a follow-on error in the type checker. Instead store a BadExpr
in the syntax tree (since an error has already been reported).

Adjust various tests.

For #54511.

Change-Id: Ib2d25f8eab7d5745275188d83d11620cad6ef47c
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- Use "expected X" rather then "expecting X".
- Report a better error when a type argument list is expected.
- Adjust various tests.

For #54511.

Change-Id: I0c5ca66ecbbdcae1a8f67377682aae6b0b6ab89a
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Use the go/types version of testdata/check tests where the diffs
are only in the error positions (the types2 test harness allows
for some position tolerance). Consolidate files where there are
other minor differences.

Comment out a couple of tests that are different between the two
type checkers.

With this CL, the testdata/check files are identical between the
two type checkers.

For #54511.

Change-Id: Ibdff2ca3ec9bdaca3aa84029a7883bb83d2d2060
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Since the check tests are now identical between the two type checkers,
remove the local copy of the check tests and (for now) use the tests
in go/types/testdata/check instead. Eventually we may decide to move
all tests out of the type checker directories and place them in a
shared space (e.g. internal/types/testdata).

For #54511.

Change-Id: Id3a97593f6c705c5eda4566089ddc7aeb7b47337
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Logic matches the code in the syntax package.
This error was missing from go/parser and go/types.
Added some tests.

For #54511.

Change-Id: I418de4bd4c7169457b424366caae70227a92a761
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Instead of checking at parse-time that the LHS of a short variable
declaration contains only identifiers, leave the check to the the
type checker which tests this already.

This removes a duplicate error and matches the behavior of the
syntax package.

For #54511.

Change-Id: I4c68f2bd8a0e015133685f9308beb98e714a83fc
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Pending CL 426477 changes go/types error messages containing the phrase:

	type parameters require

to:

	type parameter requires

Adjust diagnostics test accordingly (note that regular expressions are
currently not supported).

For golang/go#54511.

Change-Id: I561cb940a41cb6cc949c44e0d4b8f009336a46cd
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This matches the majority use case as well as types2.

For #54511.

Change-Id: If800afc35db8d32cca8329ed9d6a80b4a15c4878
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…iations

Also: add a missing test.

For #54511.

Change-Id: Ie9828c6ba5186feb5a79db0d58beb2cda2beae56
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For #54511.

Change-Id: I317c5f9beed7f1de4979ec12c6ec8d5de71bac1c
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This results in better error recovery and allows us to use the
same tests for go/types and types2.

For #54511.

Change-Id: Ic11a9dafb8c62e0cb952b3924d55a28b438241c6
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This is a port of CL 427156 from the syntax package's parser
to go/parser.

While at it, remove an unused token.Pos parameter from
parseSpecFunction and dependent declarations.

Also, consolidate the respective test file.

For #54511.

Change-Id: Id6a28eb3d23a46fa5fa1d85d2c4e634b7015513c
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For #54511.

Change-Id: I1ae391b5f157bf688f9f31b1577c90e681b6df26
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Rename .../issue46404.go1 to .../issue46404.go so that it is
not skipped anymore when running tests, and copy for types2.

Disable the code for now due to a difference in error
reporting due to the slightly different handling of index
expressions. This allows us to make progress with test
consolidation.

For #54511.

Change-Id: Ib5c9ffa49b1b24ec680ddb5001bc3dcb1df7eb1f
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Report a syntax error if the first element of a type instance is
not actually a type (but some other expression), rather then relying
on the type checker error in this case. This matches the behavior of
go/parser. Adjust the corresponding types2 test case.

For #54511.

Change-Id: Ia82b3a7d444738c56955ce6c15609470b3431fd1
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Use the go/types version of testdata/fixedbugs tests where diffs
are only in the error positions (the types2 test harness allows
for some position tolerance). Consolidate files where there are
other minor differences.

Add files to respective directories if they only existed for
one of the type checkers.

Move types2-only test issue47996.go out of testdata/fixedbugs
into testdata. Making it work for both type checkers requires
some more work.

With this CL, the testdata/fixedbugs files are identical between
the two type checkers.

For #54511.

Change-Id: I0d67f0db75ad1743c62da9181a6d0032c8bdb728
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Since the fixedbugs tests are now identical between the two type checkers,
remove the local copy of the fixedbugs tests and (for now) use the tests
in go/types/testdata/fixedbugs instead. Eventually we may decide to move
all tests out of the type checker directories and place them in a
shared space (e.g. internal/types/testdata).

For #54511.

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Establish testdata/local directory for tests that are not (yet)
shared between the go/types and types2. Move issue47996.go into
that directory.

For #54511.

Change-Id: I274b119990a93cc3657bdddc5246948699226c21
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CL 425735 consolidated the testdata/check/shifts.go files between
go/types and types2. Because some shifts don't work correctly with
types2, the corresponding tests were disabled in the shared file.
Make sure we keep testing those shifts for go/types by adding a
local test file.

For #52080.
For #54511.

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