[ASan] fix compilation of atexit_stats.cc on OSX


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@192973 91177308-0d34-0410-b5e6-96231b3b80d8
[ASan] fix compilation of sanitizer_platform_limits_posix.cc on OSX.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@192975 91177308-0d34-0410-b5e6-96231b3b80d8
[asan] reduce the size of AsanThreadContext by storing the stack trace in the stack depot

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@192979 91177308-0d34-0410-b5e6-96231b3b80d8