cmd/gc: No duplicate key error for maps with interface{} key type

[gopherbot]

by carlchatfielduntrusted:

_ = map[interface{}]int{2: 1, 2: 1}
spec: For map literals, all elements must have a key. It is an error to specify multiple
elements with the same field name or constant key value. 

What steps will reproduce the problem?
If possible, include a link to a program on play.golang.org.
http://play.golang.org/p/sfi-13X_u5

What is the expected output?
duplicate key in map literal

What do you see instead?
none

Which compiler are you using (5g, 6g, 8g, gccgo)?
6g/8g

Which operating system are you using?
linux

Which version are you using?  (run 'go version')
1.2

[minux]

Comment 1:

Interesting, it seems the check doesn't work for interfaces.
another example:
http://play.golang.org/p/EkYEd2Y3CW

Labels changed: added release-go1.3, repo-main.

Status changed to Accepted.

[rsc]

Comment 2:

Possible fix at https://golang.org/cl/82080044/

[gopherbot]

Comment 3:

This issue was closed by revision 3072df5.

Status changed to Fixed.