[PATCH] Make compiler-rt tests work with relocatable SDKs on OS X

[Kuba Brecka]

>> For the SDKROOT stuff I still think we should detect and set this automatically, mostly because other parts of LLVM/Clang are doing it already.
> Any pointers? A quick grep doesn't show any additional -isysroot flags.

lit tests (utils/lit/lit/util.py, tools/clang/test/lit.cfg, projects/compiler-rt/test/lit.common.cfg). It's only needed when you want to *run* the just built clang without doing stuff like "make install". And compiler-rt uses the newly build clang during its build phase of check-asan, so that's why we're seeing this issue.

http://reviews.llvm.org/D4047