fix Issue 10462 - interface thunk doesn't preserve EBX
Fix broken 10503

Pull request 2279 was broken, CTFE must be called AFTER resolving
properties.
Merge pull request #2288 from donc/refix10503

Repair breakage caused by pull 2279
Merge pull request #2278 from WalterBright/fix10462

fix Issue 10462 - interface thunk doesn't preserve EBX