Initial support for Haiku.

Source/Core/Common/GL/GLInterface/EGLHaiku.h

@@ -0,0 +1,16 @@
+// Copyright 2017 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "Common/GL/GLInterface/EGL.h"
+
+class cInterfaceEGLHaiku final : public cInterfaceEGL
+{
+protected:
+  EGLDisplay OpenDisplay() override;
+  EGLNativeWindowType InitializePlatform(EGLNativeWindowType host_window,
+                                         EGLConfig config) override;
+  void ShutdownPlatform() override;
+};