Fix indexes on expressions so that they can be actually used with

a COLLATE clause.

FossilOrigin-Name: e464b919f76520b45bb58983c6702db59d820ee4

src/expr.c

@@ -4680,6 +4680,17 @@ int sqlite3ExprListCompare(ExprList *pA, ExprList *pB, int iTab){
   return 0;
 }
 
+/*
+** Like sqlite3ExprCompare() except COLLATE operators at the top-level
+** are ignored.
+*/
+int sqlite3ExprCompareSkip(Expr *pA, Expr *pB, int iTab){
+  return sqlite3ExprCompare(
+             sqlite3ExprSkipCollate(pA),
+             sqlite3ExprSkipCollate(pB),
+             iTab);
+}
+
 /*
 ** Return true if we can prove the pE2 will always be true if pE1 is
 ** true.  Return false if we cannot complete the proof or if pE2 might