tsan: remember 2 stack frames for atomics (caller and atomic itself)


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@174167 91177308-0d34-0410-b5e6-96231b3b80d8
tsan: say that the memory access is atomic in reports


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@174168 91177308-0d34-0410-b5e6-96231b3b80d8