Make some pthread_mutex_* and pthread_cond_* interceptors common.

Reviewers: eugenis, dvyukov

Reviewed By: dvyukov

CC: llvm-commits

Differential Revision: http://llvm-reviews.chandlerc.com/D1937

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@192774 91177308-0d34-0410-b5e6-96231b3b80d8