QmlJS: Fix regression caused by parser update

We have to keep the semicolonToken into account.

Change-Id: Ie599d141d21f09f1d0036c0382f6a3098fde6ca5
Reviewed-by: Vikas Pachdha <vikas.pachdha@qt.io>
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

src/libs/qmljs/parser/qmljsast_p.h

@@ -1766,7 +1766,7 @@ public:
     { return expression->firstSourceLocation(); }
 
     SourceLocation lastSourceLocation() const override
-    { return expression->lastSourceLocation(); }
+    { return semicolonToken.isValid() ? semicolonToken : expression->lastSourceLocation(); }
 
 // attributes
     ExpressionNode *expression;