tsan: extend suppressions format with ^ and $ symbols
not it's possible to write more precise suppressions,
e.g. "^foo$" won't match "blafoobar"


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@186424 91177308-0d34-0410-b5e6-96231b3b80d8