Delay the variable construction in the function body. (#3289)

Local variables inside the function body should be constructed after the
parameters are initialized. Furthermore arguments should be available
during parameter initialization.

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

tests/jerry/es2015/function-param-init2.js

@@ -0,0 +1,65 @@
+// 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.
+
+function f(a, b = a)
+{
+  function a() { return 2; }
+
+  assert(a() === 2);
+  assert(b === 1)
+}
+f(1);
+
+function g(a, b = a)
+{
+  function a() { return 2; }
+
+  eval("assert(a() === 2)");
+  eval("assert(b === 1)");
+}
+g(1);
+
+var x = 1;
+function h(a = x) {
+  assert(x === undefined);
+  var x = 2;
+  assert(a === 1);
+  assert(x === 2);
+}
+h();
+
+x = function() { return 4; }
+let y = 6;
+
+function i(a = x() / 2, b = (y) + 2, c = typeof z) {
+  let y = 10;
+  let z = 11;
+
+  function x() { return 5; }
+
+  assert(a === 2);
+  assert(x() === 5);
+  assert(b === 8);
+  assert(c === "undefined");
+  assert(y === 10);
+  assert(z === 11);
+}
+i();
+
+var arguments = 10;
+function j(a = arguments[1])
+{
+  assert(a === 2);
+}
+j(undefined,2);