cmd/cgo: fix typo in gccgo name mangling recipe

The code to implement new-style gccgo name mangling had a recipe that
didn't quite match the one in the compiler (incorrect handling for
'.'). This showed up as a failure in the gotools cgo test if the
directory containing the test run included a "." character.

Change-Id: Iccbb092e7990df327c4fdbda84916e09b24516a6
Reviewed-on: https://go-review.googlesource.com/c/147917
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
1 file changed