inline assembly. For the time being, these will be called directly by clang.
However, in the near future I expect these to be sunk back into the MC layer
and more basic APIs (e.g., getClobbers(), getConstraints(), etc.) will be called
by clang.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165946 91177308-0d34-0410-b5e6-96231b3b80d8