Add instruction encodings / disassembly support for l3r instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172986 91177308-0d34-0410-b5e6-96231b3b80d8
Add instruction encodings / disassembly support for l2rus instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172987 91177308-0d34-0410-b5e6-96231b3b80d8