[msan] Implement __sanitizer_unaligned_*.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@183221 91177308-0d34-0410-b5e6-96231b3b80d8
[sanitizer] Fix __sanitizer_unaligned_* to work with unaligned data types.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@183224 91177308-0d34-0410-b5e6-96231b3b80d8