[XCore] Add missing l2rus instructions.

These instructions are not targeted by the compiler but they are
needed for the MC layer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173634 91177308-0d34-0410-b5e6-96231b3b80d8
Add special 'get' methods to create an Attribute with an alignment. Also do some random cleanup. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173635 91177308-0d34-0410-b5e6-96231b3b80d8
Don't erase these methods. They're used during testing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173636 91177308-0d34-0410-b5e6-96231b3b80d8