Add vma.cpp contains vma's implementation.

Change-Id: I1a9450530d20ddbde1a0ac07ad68a2b6d6c44029
diff --git a/vma.cpp b/vma.cpp
new file mode 100644
index 0000000..d5284f7
--- /dev/null
+++ b/vma.cpp
@@ -0,0 +1,8 @@
+// Copyright 2021 The ANGLE Project Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <vulkan/vulkan.h>
+
+#define VMA_IMPLEMENTATION
+#include "src/vk_mem_alloc.h"