* vm.c (vm_exec): refix r34162; suppress warning and add description.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@34260 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Tue Jan 10 15:31:55 2012  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* vm.c (vm_exec): refix r34162; suppress warning and add description.
+
 Tue Jan 10 15:13:58 2012  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* ext/readline/readline.c (readline_attempted_completion_function):

vm.c

@@ -1216,8 +1216,8 @@ vm_exec(rb_thread_t *th)
       vm_loop_start:
 	result = vm_exec_core(th, initial);
 	if ((state = th->state) != 0) {
-#ifdef __llvm__
-	    rb_thread_t t = *th;
+#ifdef __llvm__ /* LLVM optimization guard for TestEnumerator#test_nested_itaration */
+	    (void)__extension__({rb_thread_t t = *th; t;});
 #endif
 	    err = result;
 	    th->state = 0;