tsan: flip is_write bit in shadow to is_read
this makes calculation of interesting predicates faster


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@174164 91177308-0d34-0410-b5e6-96231b3b80d8
tsan: add flag to not report races between atomic and plain memory accesses


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@174165 91177308-0d34-0410-b5e6-96231b3b80d8