Change ObjCRuntime GenerateProtocol[Ref] methods to take

ObjCProtocolDecl directly.

Implement CodeGen support for forward protocol decls (no-ops are so
    nice to implement).

Also moved CGObjCRuntime.h out of CodeGenModule.h

llvm-svn: 54709

clang/lib/CodeGen/ModuleBuilder.cpp

@@ -72,7 +72,7 @@ namespace {
         Builder->EmitGlobal(FD);
       } else if (VarDecl *VD = dyn_cast<VarDecl>(D)) {
         Builder->EmitGlobal(VD);
-      } else if (isa<ObjCClassDecl>(D)){
+      } else if (isa<ObjCClassDecl>(D) || isa<ObjCForwardProtocolDecl>(D)) {
         //Forward declaration.  Only used for type checking.
       } else if (ObjCProtocolDecl *PD = dyn_cast<ObjCProtocolDecl>(D)){
         // Generate Protocol object.