Fix DynamicRegisterInfo copying/moving issue.

Summary:
Default copy/move constructors and assignment operators leave wrong m_sets[i].registers pointers.

Made the class movable and non-copyable (it's difficult to imagine when it needs to be copied).

Reviewers: clayborg

Reviewed By: clayborg

Differential Revision: https://reviews.llvm.org/D47728

llvm-svn: 334282