With revision 33d3e7bbd3ef, on Linux 64-bit compile the program from
http://play.golang.org/p/vcOARDUEC3 as "typecheck"

Then run:

$ go list std | grep -v cmd | xargs -n 1 ./typecheck 

The output is:

failed type check: /home/kamil/go/src/pkg/compress/lzw/reader.go:90:17: invalid
operation: mismatched types uint32 and int
failed type check: /home/kamil/go/src/pkg/debug/dwarf/buf.go:116:5: invalid operation:
mismatched types int64 and int
failed type check: /home/kamil/go/src/pkg/encoding/asn1/asn1.go:160:3: invalid
operation: mismatched types byte and int
failed type check: /home/kamil/go/src/pkg/exp/ssa/interp/interp.go:202:57: invalid
operation: instr (variable of type exp/ssa.Instruction) has no single field or method Pos
failed type check: /home/kamil/go/src/pkg/math/big/rat.go:140:15: invalid operation:
mismatched types uint64 and int
failed type check: /home/kamil/go/src/pkg/net/lookup_unix.go:56:20: undeclared name:
cgoLookupHost
failed type check: /home/kamil/go/src/pkg/os/types.go:64:6: invalid operation:
mismatched types FileMode and int
failed type check: /home/kamil/go/src/pkg/os/user/lookup.go:9:9: undeclared name: current
failed type check: /home/kamil/go/src/pkg/runtime/softfloat64.go:234:11: invalid
operation: mismatched types uint64 and int
failed type check: /home/kamil/go/src/pkg/strconv/atof.go:326:5: invalid operation:
cannot compare mant (variable of type uint64) == 2 << flt.mantbits (value of type
int)
failed type check: /home/kamil/go/src/pkg/text/scanner/scanner.go:540:6: invalid
operation: mismatched types uint64 and int

The errors regarding "mistmatched types T and int" refer to lines that look
like (example from the last line of output):

for s.Whitespace&(1<<uint(ch)) != 0 {

so it seems like the types package has trouble determining the correct type for the
shift expression.