cmd/go: rewrite TestCgoFlagContainsSpace not to use a fake CC
Using a fake CC fails today if runtime/cgo is stale, because the
build will try to rebuild runtime/cgo using the fake CC, and the
fake CC is not a working C compiler.
Worse, in the future, when the go command is sensitive to details like
the fact that different CCs produce different outputs, putting in
the fake CC will make runtime/cgo look stale even if it was
formerly up-to-date.
Fix both problems by not overriding CC and instead looking at
the command being run to make sure the flags are quoted as expected.
Change-Id: I4417e35cfab33a07546cc90748ddb6119d8fdb2d
Reviewed-on: https://go-review.googlesource.com/56272
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Ian Lance Taylor <iant@golang.org>