Allow arbitrary expressions in new/instanceof using () syntax

Zend/tests/varSyntax/new_instanceof_expr.phpt

@@ -0,0 +1,18 @@
+--TEST--
+new with an arbitrary expression
+--FILE--
+<?php
+
+$class = 'class';
+var_dump(new ('std'.$class));
+var_dump(new ('std'.$class)());
+$obj = new stdClass;
+var_dump($obj instanceof ('std'.$class));
+
+?>
+--EXPECT--
+object(stdClass)#1 (0) {
+}
+object(stdClass)#1 (0) {
+}
+bool(true)

Zend/zend_language_parser.y

@@ -1078,6 +1078,7 @@ class_name:
 class_name_reference:
 		class_name		{ $$ = $1; }
 	|	new_variable	{ $$ = $1; }
+	|	'(' expr ')'	{ $$ = $2; }
 ;
 
 exit_expr: