Revert "Implement std::condition_variable via pthread_cond_clockwait() where available"

This reverts commit 5e37d7f9ff257ec62d733d3d94b11f03e0fe51ca.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@372034 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed