tsan: allow to suppress all reports
Fixes issue https://code.google.com/p/thread-sanitizer/issues/detail?id=45



git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@207218 91177308-0d34-0410-b5e6-96231b3b80d8
[ASan] Use a non-null altstack.ss_size when disabling sigaltstack on Darwin.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@207220 91177308-0d34-0410-b5e6-96231b3b80d8