operator* on the by-operand iterators to return a MachineOperand& rather than
a MachineInstr&. At this point they almost behave like normal iterators!
Again, this requires making some existing loops more verbose, but should pave
the way for the big range-based for-loop cleanups in the future.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203865 91177308-0d34-0410-b5e6-96231b3b80d8