[PATCH] Don't check clang binary name, as it can be different in some test setups.

[Alexander Kornienko]

>>! In D4311#4, @benlangmuir wrote:
> We have these kinds of checks in a lot of the other Driver tests. Should we update those as well (in general, not necessarily for this patch)?

We have to either specify -no-canonical-prefixes with each clang invocation in tests, or don't check clang binary name. Most of the tests do one of this things already, all the rest should do this. The tests are not consistent in choosing one of these options, so here I've chosen the simplest one.

http://reviews.llvm.org/D4311