lupdate: Allow trailing commas in QtScript/JS object literals

As per ECMA-262 5th edition, section 11.1.5, trailing commas should
be allowed in object literals. E.g.

{ foo: 10, }

shouldn't cause a syntax error; the comma should simply be ignored.

Task-number: QTBUG-22970
Change-Id: I3e730ad3001760475e5e40bb4a28a05b0baf5c7e
Sanity-Review: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Roberto Raggi <roberto.raggi@nokia.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@nokia.com>

src/linguist/lupdate/qscript.g

@@ -1641,6 +1641,7 @@ PrimaryExpression: T_LBRACKET ElisionOpt T_RBRACKET ;
 PrimaryExpression: T_LBRACKET ElementList T_RBRACKET ;
 PrimaryExpression: T_LBRACKET ElementList T_COMMA ElisionOpt T_RBRACKET ;
 PrimaryExpression: T_LBRACE PropertyNameAndValueListOpt T_RBRACE ;
+PrimaryExpression: T_LBRACE PropertyNameAndValueList T_COMMA T_RBRACE ;
 PrimaryExpression: T_LPAREN Expression T_RPAREN ;
 ElementList: ElisionOpt AssignmentExpression ;
 ElementList: ElementList T_COMMA ElisionOpt AssignmentExpression ;

tests/auto/linguist/lupdate/testdata/good/parsejs3/main.js

+({ foo: 123, }) // Trailing comma shouldn't cause syntax error and bailout
+
+({ foo: qsTr("one") })
+
+({ foo: qsTr("two"), })
+
+({ foo: qsTranslate("FooContext", "one") })
+
+({ foo: qsTranslate("FooContext", "two"), })
+
+({ foo: qsTrId("qtn_foo_bar") })
+
+({ foo: qsTrId("qtn_bar_baz"), })
+
+({ foo: { bar: 123, }, baz: qsTr("three"), })
+
+({ foo: { bar: 123, }, baz: qsTranslate("FooContext", "three"), })
+
+({
+    firstGuy: {
+        age: 50,
+        //: First guy first name
+        firstName: qsTr("Frits"),
+        //: First guy middle name
+        middleName: qsTranslate("BarContext", "Joe"),
+        //% "First guy last name"
+        lastName: qsTrId("qtn_first_guy_last_name"),
+        weight: 100, // Uh-oh, trailing comma!
+    },
+    secondGuy: {
+        age: 70,
+        //: Second guy first name
+        firstName: qsTr("Bob"),
+        //: Second guy middle name
+        middleName: qsTranslate("BarContext", "Steve"),
+        //% "Second guy last name"
+        lastName: qsTrId("qtn_second_guy_last_name"),
+        weight: 120, // Uh-oh, trailing comma!
+    },
+})

tests/auto/linguist/lupdate/testdata/good/parsejs3/project.pro

+SOURCES += main.js
+
+TRANSLATIONS = project.ts

tests/auto/linguist/lupdate/testdata/good/parsejs3/project.ts.result

+<?xml version="1.0" encoding="utf-8"?>
+<!DOCTYPE TS>
+<TS version="2.0">
+<context>
+    <name></name>
+    <message id="qtn_foo_bar">
+        <location filename="main.js" line="11"/>
+        <source></source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message id="qtn_bar_baz">
+        <location filename="main.js" line="13"/>
+        <source></source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message id="qtn_first_guy_last_name">
+        <location filename="main.js" line="27"/>
+        <source>First guy last name</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message id="qtn_second_guy_last_name">
+        <location filename="main.js" line="37"/>
+        <source>Second guy last name</source>
+        <translation type="unfinished"></translation>
+    </message>
+</context>
+<context>
+    <name>BarContext</name>
+    <message>
+        <location filename="main.js" line="25"/>
+        <source>Joe</source>
+        <extracomment>First guy middle name</extracomment>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="main.js" line="35"/>
+        <source>Steve</source>
+        <extracomment>Second guy middle name</extracomment>
+        <translation type="unfinished"></translation>
+    </message>
+</context>
+<context>
+    <name>FooContext</name>
+    <message>
+        <location filename="main.js" line="7"/>
+        <source>one</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="main.js" line="9"/>
+        <source>two</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="main.js" line="17"/>
+        <source>three</source>
+        <translation type="unfinished"></translation>
+    </message>
+</context>
+<context>
+    <name>main</name>
+    <message>
+        <location filename="main.js" line="3"/>
+        <source>one</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="main.js" line="5"/>
+        <source>two</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="main.js" line="15"/>
+        <source>three</source>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="main.js" line="23"/>
+        <source>Frits</source>
+        <extracomment>First guy first name</extracomment>
+        <translation type="unfinished"></translation>
+    </message>
+    <message>
+        <location filename="main.js" line="33"/>
+        <source>Bob</source>
+        <extracomment>Second guy first name</extracomment>
+        <translation type="unfinished"></translation>
+    </message>
+</context>
+</TS>