[TSan] Add -lpthread to the test which uses pthread_ functions

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@215939 91177308-0d34-0410-b5e6-96231b3b80d8
Add regression test for PR15823

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@215941 91177308-0d34-0410-b5e6-96231b3b80d8