This patch updates libc++abi's HandleOutOfTreeLLVM.cmake to match
libc++'s -- and more importantly, to fix a bug where llvm-lit wasn't
found/created when libc++abi was built out-of-tree. This prevented
the test suite from running.
llvm-svn: 322768
Refactor cmake to remove dependence on LLVM's cmake modules.
This improves handling of cmake checks when cross compiling and brings
libcxxabi in line with libcxx and other project modules.
Differential revision: https://reviews.llvm.org/D33635
llvm-svn: 304374