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/mirror/method.h b/runtime/mirror/method.h
new file mode 100644
index 0000000..88100f0
--- /dev/null
+++ b/runtime/mirror/method.h
@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_RUNTIME_MIRROR_METHOD_H_
+#define ART_RUNTIME_MIRROR_METHOD_H_
+
+#include "abstract_method.h"
+#include "gc_root.h"
+
+namespace art {
+namespace mirror {
+
+class Class;
+
+// C++ mirror of java.lang.reflect.Method.
+class MANAGED Method : public AbstractMethod {
+ public:
+  static Method* CreateFromArtMethod(Thread* self, mirror::ArtMethod* method)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  static mirror::Class* StaticClass() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    return static_class_.Read();
+  }
+
+  static void SetClass(Class* klass) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  static void ResetClass() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  static mirror::Class* ArrayClass() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    return array_class_.Read();
+  }
+
+  static void SetArrayClass(Class* klass) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  static void ResetArrayClass() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  static void VisitRoots(RootVisitor* visitor) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+ private:
+  static GcRoot<Class> static_class_;  // java.lang.reflect.Method.class.
+  static GcRoot<Class> array_class_;  // [java.lang.reflect.Method.class.
+
+  DISALLOW_COPY_AND_ASSIGN(Method);
+};
+
+// C++ mirror of java.lang.reflect.Constructor.
+class MANAGED Constructor: public AbstractMethod {
+ public:
+  static Constructor* CreateFromArtMethod(Thread* self, mirror::ArtMethod* method)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  static mirror::Class* StaticClass() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    return static_class_.Read();
+  }
+
+  static void SetClass(Class* klass) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  static void ResetClass() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  static mirror::Class* ArrayClass() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    return array_class_.Read();
+  }
+
+  static void SetArrayClass(Class* klass) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  static void ResetArrayClass() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  static void VisitRoots(RootVisitor* visitor) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+ private:
+  static GcRoot<Class> static_class_;  // java.lang.reflect.Constructor.class.
+  static GcRoot<Class> array_class_;  // [java.lang.reflect.Constructor.class.
+
+  DISALLOW_COPY_AND_ASSIGN(Constructor);
+};
+
+}  // namespace mirror
+}  // namespace art
+
+#endif  // ART_RUNTIME_MIRROR_METHOD_H_