Tweak Sema::ActOnInstanceMessage() to look for a class method when dealing with qualified id's. This change is motivated by our desire to not support the "Class<foo>" idiom. Note that the change makes perfect sense (since all ObjC classes are also id/instances).

This allow us to document a simple migration path...change "Class <foo>" to "id <foo>".

This effects: 
- <rdar://problem/6761939> TASK: File source change radars for "qualified Class" errors
- <rdar://problem/6761864> Protocol qualified Class is unsupported


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@68517 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaExprObjC.cpp b/lib/Sema/SemaExprObjC.cpp
index cfa279a..54ed709 100644
--- a/lib/Sema/SemaExprObjC.cpp
+++ b/lib/Sema/SemaExprObjC.cpp
@@ -548,6 +548,9 @@
       ObjCProtocolDecl *PDecl = QIT->getProtocols(i);
       if (PDecl && (Method = PDecl->lookupInstanceMethod(Sel)))
         break;
+      // Since we aren't supporting "Class<foo>", look for a class method.
+      if (PDecl && (Method = PDecl->lookupClassMethod(Sel)))
+        break;
     }
   } else if (const ObjCInterfaceType *OCIType = 
                 ReceiverCType->getAsPointerToObjCInterfaceType()) {