code review 5758063: misc/cgo/test: fix build

misc/cgo/test: fix build

The last CL forgot the all-important 'backdoor' package.
Cgo-using packages compile .c files with gcc, but we want
to compile this one with 6c, so put it in a non-cgo package.

[rsc, 2012-03-07 04:38:52]

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

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

[rsc, 2012-03-07 04:38:56]

*** Submitted as fdb871a77eef ***

misc/cgo/test: fix build

The last CL forgot the all-important 'backdoor' package.
Cgo-using packages compile .c files with gcc, but we want
to compile this one with 6c, so put it in a non-cgo package.

TBR=golang-dev
CC=golang-dev
http://codereview.appspot.com/5758063

[r, 2012-03-07 04:39:58]

LGTM