Fix indexes on expressions so that they can be actually used with
a COLLATE clause.

FossilOrigin-Name: e464b919f76520b45bb58983c6702db59d820ee4
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index f976889..23b4dd94 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -3762,6 +3762,7 @@
 int sqlite3RunVacuum(char**, sqlite3*, int);
 char *sqlite3NameFromToken(sqlite3*, Token*);
 int sqlite3ExprCompare(Expr*, Expr*, int);
+int sqlite3ExprCompareSkip(Expr*, Expr*, int);
 int sqlite3ExprListCompare(ExprList*, ExprList*, int);
 int sqlite3ExprImpliesExpr(Expr*, Expr*, int);
 void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);