[msan] Limit stack origin chain length.

Stack origins were created with unlimited length by mistake.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@212036 91177308-0d34-0410-b5e6-96231b3b80d8
Fix apparent thinko in r209744: allocator stats can be zero

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@212071 91177308-0d34-0410-b5e6-96231b3b80d8
Add the way to disable MSan unit tests for _mm_* intrinsics

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@212082 91177308-0d34-0410-b5e6-96231b3b80d8