[CodeGen] Separate MachineOperand implementation from MachineInstr

Move the implementation to its own file.

Differential Revision: https://reviews.llvm.org/D40419

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319194 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed