[Statepoint lowering] Require spill of deopt value in case its type is not legal

If the type of the deopt operand has an illegal type and we want to use
register for it then it needs to be legalized.
This is not supported currently by legalizer and it is not actually clear how to
legalize this type of values.

Instead we just spill such values and use spill slot location in statepoint.

Originally tests were created by Philip Reames.

Reviewers: reames, dantrushin
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D97541