[cfe-dev] Clang "Hacking" doc seems outdated...

[Renato Golin via cfe-dev]

http://clang.llvm.org/hacking.html#testingNonWindows

Especially the part which says "run make test from the top-level clang
directory", or "the test suite can be run with make clang-test from
the top-level LLVM directory".

I'm not really sure what that was supposed to mean, so I won't change
them myself. But it would actually be better to point at the official
testing documentation, which is much better nowadays.

cheers,
--renato