Eliminate RawClass::patch_class_ field

runtime/vm/compiler.cc

Index: runtime/vm/compiler.cc
diff --git a/runtime/vm/compiler.cc b/runtime/vm/compiler.cc
index 5d683ce5aa8c39bb29773d98e8b7566a00e9adb5..6655af303bb89fda05a02c6a3a3da60a6eca7891 100644
--- a/runtime/vm/compiler.cc
+++ b/runtime/vm/compiler.cc
@@ -249,7 +249,7 @@ static void AddRelatedClassesToList(
   // Add patch classes if they exist to the parse list if they have not already
   // been parsed and patched. Mark the class as parsed so that we don't
   // recursively add it back into the list.
-  parse_class ^= cls.patch_class();
+  parse_class ^= cls.GetPatchClass();
   if (!parse_class.IsNull()) {
     if (!parse_class.is_finalized() && !parse_class.is_marked_for_parsing()) {
       patch_list->Add(parse_class);