-Wdeprecated-clean: Fix cases of violating the rule of 5 in ways that are deprecated...

-Wdeprecated-clean: Fix cases of violating the rule of 5 in ways that are deprecated in C++11

Various targets use std::swap on specific MCAsmOperands (ARM and
possibly Hexagon as well). It might be helpful to mark those subclasses
as final, to ensure that the availability of move/copy operations can't
lead to slicing. (same sort of requirements as the non-vitual dtor -
protected or a final class)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@243820 91177308-0d34-0410-b5e6-96231b3b80d8