code review 7008045: cmd/gc: add diagnostic for var, type, const named init

cmd/gc: add diagnostic for var, type, const named init

Before this CL, defining the variable worked fine, but then when
the implicit package-level init func was created, that caused a
name collision and a confusing error about the redeclaration.

Also add a test for issue 3705 (func init() needs body).

Fixes issue 4517.

[rsc, 2012-12-22 22:23:27]

Hello ken2 (cc: golang-dev@googlegroups.com),

I'd like you to review this change to
https://code.google.com/p/go/

[rsc, 2012-12-22 22:23:37]

*** Submitted as https://code.google.com/p/go/source/detail?r=33b15f6ddadb ***

cmd/gc: add diagnostic for var, type, const named init

Before this CL, defining the variable worked fine, but then when
the implicit package-level init func was created, that caused a
name collision and a confusing error about the redeclaration.

Also add a test for issue 3705 (func init() needs body).

Fixes issue 4517.

R=ken2
CC=golang-dev
https://codereview.appspot.com/7008045

[ken3, 2012-12-22 22:28:01]

lgtm