Update lib/Sema/MiscDiagnostics.cpp

Co-authored-by: Suyash Srijan <[email protected]>

Author: calda

lib/Sema/MiscDiagnostics.cpp

@@ -1353,7 +1353,7 @@ static void diagSyntacticUseRestrictions(const Expr *E, const DeclContext *DC,
             (isTypeCheckedOptionalNil(lhs) &&
              (subExpr = isImplicitPromotionToOptional(rhs)))) {
           bool isTrue = calleeName == "!=" || calleeName == "!==";
-          bool isNilLiteral = dyn_cast<NilLiteralExpr>(lhs) || dyn_cast<NilLiteralExpr>(rhs);
+          bool isNilLiteral = isa<NilLiteralExpr>(lhs) || isa<NilLiteralExpr>(rhs);
 
           Ctx.Diags.diagnose(DRE->getLoc(), diag::nonoptional_compare_to_nil,
                              subExpr->getType(), isNilLiteral, isTrue)