Fix for issue 32731 (#33534)

Fix for issue 32731 (#33534)

* Couple of crossgen2 fixes:
1) Fix an issue hitting an assert in the TypeSystem's virtual function resolution
2) Port some inlining rules from crossgen1 - One of them fixes an issue where we would incorrectly inline a virtual method that has a MethodImpl associated with it (test = self_override5)
3) Remove an assert from R2RDump related to the composite work (assert needs to be after loading _readyToRunHeaderRVA, and is actually already at the right place a few lines below)