Fix prop_getters stack manipulation for assignment expression.

Related issue: #614

JerryScript-DCO-1.0-Signed-off-by: Ilyong Cho ily.cho@samsung.com

tests/jerry/regression-test-issue-614.js

@@ -0,0 +1,26 @@
+// Copyright 2015 Samsung Electronics Co., Ltd.
+// Copyright 2015 University of Szeged.
+//
+// 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.
+
+JSON.stringify & (Date = 1);
+
+b = 1;
+this.a = 2;
+this.a
+b = 3;
+assert(b == 3);
+assert(a == 2);
+this.a & (b = 4);
+assert(b == 4);
+assert(a == 2);