[msan] Increase stack size as required.

Adjust stack size in pthread_attr_t when the app-requested size does not fit MSan TLS.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@176939 91177308-0d34-0410-b5e6-96231b3b80d8
[Sanitizer] Build ASan, TSan and MSan runtimes with -fno-rtti.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@176940 91177308-0d34-0410-b5e6-96231b3b80d8