Fix Issue 10682 - [ICE](cgcod.c line 1561) with ^^ operator

The backend can't handle a shift expression with a ulong rhs, so simulate the cast that is usually added by semantic.
revert pull 1325
Merge pull request #2547 from WalterBright/revert-pull-1325

revert pull 1325
Merge pull request #2528 from yebblies/issue10682

Fix Issue 10682 - [ICE](cgcod.c line 1561) with ^^ operator