Qml/js reformatter: use quotes in objects literals

The reformatter used to remove the quotes that wraps the property name
in object literals.  This causes problem when the name is not a
valid identifier, resulting in that valid code become invalid after
reformatting.
This patch forces wrapping of property's name in quotes: in this way,
the reformatted code is consistent and it never get invalidated.

However the resulting formatted code is not consisted with the one
formatted by previous versions.

Task-number: QTCREATORBUG-17455
Change-Id: I1e361102819055de210d6c81020f204c08aaa253
Reviewed-by: Markus Maier <markus.maier.sw@gmail.com>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

src/libs/qmljs/qmljsreformatter.cpp

@@ -687,7 +687,9 @@ protected:
         for (PropertyAssignmentList *it = ast; it; it = it->next) {
             PropertyNameAndValue *assignment = AST::cast<PropertyNameAndValue *>(it->assignment);
             if (assignment) {
+                out("\"");
                 accept(assignment->name);
+                out("\"");
                 out(": ", assignment->colonToken);
                 accept(assignment->value);
                 if (it->next) {

tests/auto/qml/reformatter/objectliteral.js

@@ -1,12 +1,12 @@
 var x = {
-    x: 12,
-    y: {
-        x: 12,
-        y: "abc",
-        z: function (x) {
+    "x": 12,
+    "y": {
+        "x": 12,
+        "y": "abc",
+        "z": function (x) {
             return a
         },
-        abc: 15
+        "abc": 15
     },
-    z: 12
+    "z": 12
 }