Add AbstractMethod, Constructor, Method

Moves functionality to ART from libcore. Precursor to moving
ArtMethods to native. Mostly performance improvements.

N5 perf before (irrelevant results removed):
            Class_getConstructor  962.87 ===========
         Class_getDeclaredMethod 2394.37 ============================
                 Class_getMethod 2509.20 ==============================
               Class_newInstance 1999.81 =======================
                  Method_invokeI 1439.02 =================
          Method_invokePreBoxedI 1415.82 ================
            Method_invokeStaticI 1456.24 =================
    Method_invokeStaticPreBoxedI 1427.32 =================
            Method_invokeStaticV  814.47 =========
                  Method_invokeV  816.56 =========
After:
                       benchmark      ns linear runtime
            Class_getConstructor 1302.04 ================
         Class_getDeclaredMethod 1459.01 ==================
                 Class_getMethod 1560.40 ===================
               Class_newInstance 2029.94 =========================
                  Method_invokeI 1312.89 ================
          Method_invokePreBoxedI 1255.01 ===============
            Method_invokeStaticI 1289.13 ===============
    Method_invokeStaticPreBoxedI 1196.52 ==============
            Method_invokeStaticV  790.82 =========
                  Method_invokeV  791.73 =========

Performance improvements are more than just fixing regressions introduced
in: http://android-review.googlesource.com/#/c/146069/

Bug: 19264997

Change-Id: Ife79c469fdb09f30e3aefcfc3e0ce5ed32303fce
diff --git a/runtime/native/java_lang_reflect_Proxy.cc b/runtime/native/java_lang_reflect_Proxy.cc
index baf8b24..4a6ab40 100644
--- a/runtime/native/java_lang_reflect_Proxy.cc
+++ b/runtime/native/java_lang_reflect_Proxy.cc
@@ -30,13 +30,12 @@
                                   jobject loader, jobjectArray methods, jobjectArray throws) {
   ScopedFastNativeObjectAccess soa(env);
   ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
-  mirror::Class* result = class_linker->CreateProxyClass(soa, name, interfaces, loader, methods,
-                                                         throws);
-  return soa.AddLocalReference<jclass>(result);
+  return soa.AddLocalReference<jclass>(class_linker->CreateProxyClass(
+      soa, name, interfaces, loader, methods, throws));
 }
 
 static JNINativeMethod gMethods[] = {
-  NATIVE_METHOD(Proxy, generateProxy, "!(Ljava/lang/String;[Ljava/lang/Class;Ljava/lang/ClassLoader;[Ljava/lang/reflect/ArtMethod;[[Ljava/lang/Class;)Ljava/lang/Class;"),
+  NATIVE_METHOD(Proxy, generateProxy, "!(Ljava/lang/String;[Ljava/lang/Class;Ljava/lang/ClassLoader;[Ljava/lang/reflect/Method;[[Ljava/lang/Class;)Ljava/lang/Class;"),
 };
 
 void register_java_lang_reflect_Proxy(JNIEnv* env) {