[msan] Origin tracking with history, compiler-rt part.

Compiler-rt part of MSan implementation of advanced origin tracking,
when we record not only creation point, but all locations where
an uninitialized value was stored to memory, too.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@204152 91177308-0d34-0410-b5e6-96231b3b80d8