[RegisterClassInfo] Invalidate cached information if ignoreCSRForAllocationOrder changes

Even if CSR list is same between functions, we could have had a different
allocation order if ignoreCSRForAllocationOrder is evaluated differently.
Hence invalidate cached register class information if
ignoreCSRForAllocationOrder changes.

Patch by Srividya Karumuri <srividya_karumuri@apple.com>

Differential Revision: https://reviews.llvm.org/D126565