[sanitizer] fully implement racy fast path in bitset-based deadlock detector

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@203910 91177308-0d34-0410-b5e6-96231b3b80d8
[CMake] Add trailing newline to test source file to make sure -Wnewline-eof doesn't fire

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@203911 91177308-0d34-0410-b5e6-96231b3b80d8