[PATCH] Don't build tests for compiler-rt libs that aren't supported

[Alexey Samsonov]

What CMake invocation produces such errors?

Anyway, this patch brings up a valid issue, but I think we should better determine which sanitizers are actually going to be built in the top-level CMakeLists.txt (or move this logic to some helper module). Let me know if you will update the patch, otherwise I'll make this change myself.

http://reviews.llvm.org/D4709