Suppress a warning

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@63310 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDeclObjC.cpp b/lib/Sema/SemaDeclObjC.cpp
index 3371e3e..5677bc5 100644
--- a/lib/Sema/SemaDeclObjC.cpp
+++ b/lib/Sema/SemaDeclObjC.cpp
@@ -1432,8 +1432,8 @@
                           "copy" : "retain";
                          
     Diag(Loc, (Attributes & (ObjCDeclSpec::DQ_PR_readwrite)) ? 
-                 diag::err_objc_property_attr_mutually_exclusive :
-                 diag::warn_objc_property_attr_mutually_exclusive)
+                 (unsigned)diag::err_objc_property_attr_mutually_exclusive :
+                 (unsigned)diag::warn_objc_property_attr_mutually_exclusive)
       << "readonly" << which;
   }