Refactor code to use ToInteger (#3224)

Fixes #3325
Fixes #3237

JerryScript-DCO-1.0-Signed-off-by: Daniella Barsony bella@inf.u-szeged.hu

tests/jerry/regression-test-issue-3325.js

@@ -0,0 +1,23 @@
+// Copyright JS Foundation and other contributors, http://js.foundation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+var text = 'x';
+assert (text.charAt(0) === "x");
+assert (text.charAt(-0.1) === "x");
+assert (text.charAt(-0.5) === "x");
+assert (text.charAt(-0.9) === "x");
+assert (text.charAt(0.85) === "x");
+
+assert (text.charAt(-0.5) !== "");
+assert (text.charAt(0.85) !== "");