[PATCH] Add AArch64 support to CMake

[Tim Northover]

  Hi Renato,

  I can't see why using targets_to_build is the right thing to do for ExecutionEngine. Doesn't this patch mean that the tests will be completely disabled even on our default "build everything that moves" configuration, simply because they *also* have the problematic architectures?

  The most likely issue, from memory, is that CMake means different things by host, target & build than autotools so the CMakeLists.txt files look a little unnatural when setting up llvm-lit ("if host == XYZ, set llvm-lit.target = XYZ" or similar). That might be the place to look for the bug.

  Cheers.

  Tim.

http://llvm-reviews.chandlerc.com/D2825