Some refactoring of Ivar offset code gen.
in preparation for nonfragile ivar offset work.

llvm-svn: 64225
diff --git a/clang/lib/CodeGen/CGObjCRuntime.h b/clang/lib/CodeGen/CGObjCRuntime.h
index c85e9deb..1513157 100644
--- a/clang/lib/CodeGen/CGObjCRuntime.h
+++ b/clang/lib/CodeGen/CGObjCRuntime.h
@@ -163,6 +163,9 @@
                                       const ObjCIvarDecl *Ivar,
                                       const FieldDecl *Field,
                                       unsigned CVRQualifiers) = 0;
+  virtual llvm::Value *EmitIvarOffset(CodeGen::CodeGenFunction &CGF,
+                                      ObjCInterfaceDecl *Interface,
+                                      const ObjCIvarDecl *Ivar) = 0;
 };
 
 /// Creates an instance of an Objective-C runtime class.