[Backport] C2CodeStubList should be ResourceObj

Summary: Fix jtreg nightly failure due to backport 8291555.

Test Plan: CICD

Reviewed-by: kuaiwei,yifeng

Issue: #685

src/hotspot/share/opto/c2_CodeStubs.hpp

@@ -50,7 +50,7 @@ class C2CodeStub : public ResourceObj {
   virtual int max_size() const = 0;
 };
 
-class C2CodeStubList {
+class C2CodeStubList : public ResourceObj {
 private:
   GrowableArray<C2CodeStub*>* _stubs;