tsan: add interceptor stubs for stat family of functions


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@173782 91177308-0d34-0410-b5e6-96231b3b80d8
tsan: add IsSymbolizerAvailable() function for querying for presence of internal/external symbolizer


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@173783 91177308-0d34-0410-b5e6-96231b3b80d8
tsan: fix the message (tsan is not asan)


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@173784 91177308-0d34-0410-b5e6-96231b3b80d8