Start implementing support for @synchonized with the darwin ObjC API.

Patch by Fariborz!



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@59377 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGStmt.cpp b/lib/CodeGen/CGStmt.cpp
index 767e275..3f2cd80 100644
--- a/lib/CodeGen/CGStmt.cpp
+++ b/lib/CodeGen/CGStmt.cpp
@@ -92,7 +92,7 @@
     EmitObjCAtThrowStmt(cast<ObjCAtThrowStmt>(*S));
     break;
   case Stmt::ObjCAtSynchronizedStmtClass:
-    ErrorUnsupported(S, "@synchronized statement");
+    EmitObjCAtSynchronizedStmt(cast<ObjCAtSynchronizedStmt>(*S));
     break;
   case Stmt::ObjCForCollectionStmtClass: 
     EmitObjCForCollectionStmt(cast<ObjCForCollectionStmt>(*S));