Summary:
This patch adds CMake support for building and testing libc++abi without threads.
1. Add `LIBCXXABI_ENABLE_THREADS` option to CMake.
2. Propagate `LIBCXXABI_ENABLE_THREADS` to lit via lit.site.cfg.in
3. Configure tests for `LIBCXXABI_ENABLE_THREADS=OFF
Currently the test suite does not work when libc++abi is built without threads because that information does not propagate to the test suite.
Reviewers: danalbert, mclow.lists, jroelofs
Reviewed By: jroelofs
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D6393
llvm-svn: 222702
Also remove the audotedection part so that if you're crazy enough to want a
single-threaded abi library, you'll say so explicitly in the build.
llvm-svn: 217262