fix openjdk-src build (oversight from type-generator refactor)

src/avian/machine.h

@@ -2437,16 +2437,16 @@ object findFieldInClass(Thread* t,
                         GcByteArray* name,
                         GcByteArray* spec);
 
-inline object findFieldInClass2(Thread* t,
-                                GcClass* class_,
-                                const char* name,
-                                const char* spec)
+inline GcField* findFieldInClass2(Thread* t,
+                                  GcClass* class_,
+                                  const char* name,
+                                  const char* spec)
 {
   PROTECT(t, class_);
   GcByteArray* n = makeByteArray(t, "%s", name);
   PROTECT(t, n);
   GcByteArray* s = makeByteArray(t, "%s", spec);
-  return findFieldInClass(t, class_, n, s);
+  return cast<GcField>(t, findFieldInClass(t, class_, n, s));
 }
 
 object findMethodInClass(Thread* t,

src/avian/util.h

@@ -90,7 +90,7 @@ void listAppend(Thread* t, GcList* list, object value);
 
 GcVector* vectorAppend(Thread* t, GcVector* vector, object value);
 
-object growArray(Thread* t, object array);
+GcArray* growArray(Thread* t, GcArray* array);
 
 object treeQuery(Thread* t,
                  GcTreeNode* tree,