Revert^2 "Add AddToDexClassloader JVMTI extension functions"

This reverts commit 799e536da9733ab638946f56e1ceb62d62cd3c81.

It seems that on some of our test devices the kernel does not have an
implementation for memfd_create. To work around this I added a basic
wrapper that will simulate memfd_create using temp files. This should
be sufficient for testing. All actual devices are expected to support
the memfd_create syscall natively.

Reason for revert: Implemented fallback for memfd_create
Bug: 132699522
Bug: 132914283
Test: ./test.py --host

Change-Id: I63b36464df24193fff27624c1e2350d65545ad1d
diff --git a/test/1963-add-to-dex-classloader-in-memory/add_to_loader.cc b/test/1963-add-to-dex-classloader-in-memory/add_to_loader.cc
new file mode 100644
index 0000000..1c3f36d
--- /dev/null
+++ b/test/1963-add-to-dex-classloader-in-memory/add_to_loader.cc
@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#include <atomic>
+
+#include "jvmti.h"
+
+// Test infrastructure
+#include "jvmti_helper.h"
+#include "scoped_local_ref.h"
+#include "test_env.h"
+
+namespace art {
+namespace Test1963AddToDexClassLoaderInMemory {
+
+using AddToDexClassLoaderInMemory = jvmtiError (*)(jvmtiEnv* env,
+                                                   jobject loader,
+                                                   const unsigned char* dex_file,
+                                                   jint dex_file_length);
+
+template <typename T> static void Dealloc(T* t) {
+  jvmti_env->Deallocate(reinterpret_cast<unsigned char*>(t));
+}
+
+template <typename T, typename... Rest> static void Dealloc(T* t, Rest... rs) {
+  Dealloc(t);
+  Dealloc(rs...);
+}
+static void DeallocParams(jvmtiParamInfo* params, jint n_params) {
+  for (jint i = 0; i < n_params; i++) {
+    Dealloc(params[i].name);
+  }
+}
+
+AddToDexClassLoaderInMemory GetAddFunction(JNIEnv* env) {
+  // Get the extensions.
+  jint n_ext = 0;
+  jvmtiExtensionFunctionInfo* infos = nullptr;
+  if (JvmtiErrorToException(env, jvmti_env, jvmti_env->GetExtensionFunctions(&n_ext, &infos))) {
+    return nullptr;
+  }
+  AddToDexClassLoaderInMemory result = nullptr;
+  for (jint i = 0; i < n_ext; i++) {
+    jvmtiExtensionFunctionInfo* cur_info = &infos[i];
+    if (strcmp("com.android.art.classloader.add_to_dex_class_loader_in_memory", cur_info->id) ==
+        0) {
+      result = reinterpret_cast<AddToDexClassLoaderInMemory>(cur_info->func);
+    }
+    // Cleanup the cur_info
+    DeallocParams(cur_info->params, cur_info->param_count);
+    Dealloc(cur_info->id, cur_info->short_description, cur_info->params, cur_info->errors);
+  }
+  // Cleanup the array.
+  Dealloc(infos);
+  return result;
+}
+
+extern "C" JNIEXPORT void JNICALL Java_art_Test1963_addToClassLoaderNative(JNIEnv* env,
+                                                                           jclass,
+                                                                           jobject loader,
+                                                                           jobject bytebuffer) {
+  AddToDexClassLoaderInMemory add_func = GetAddFunction(env);
+  if (add_func == nullptr) {
+    env->ThrowNew(env->FindClass("java/lang/RuntimeError"), "Failed to find extension function");
+    return;
+  }
+  JvmtiErrorToException(
+      env,
+      jvmti_env,
+      add_func(jvmti_env,
+               loader,
+               reinterpret_cast<unsigned char*>(env->GetDirectBufferAddress(bytebuffer)),
+               env->GetDirectBufferCapacity(bytebuffer)));
+}
+
+}  // namespace Test1963AddToDexClassLoaderInMemory
+}  // namespace art