Initial refactoring of gpu/.

Runs too fast - now there are ringbuffer wrapping issues.

src/xenia/gpu/buffer_resource.cc

@@ -15,3 +15,42 @@ using namespace xe;
 using namespace xe::gpu;
 using namespace xe::gpu::xenos;
 
+
+BufferResource::BufferResource(const MemoryRange& memory_range)
+    : PagedResource(memory_range) {
+}
+
+BufferResource::~BufferResource() = default;
+
+int BufferResource::Prepare() {
+  if (!handle()) {
+    if (CreateHandle()) {
+      XELOGE("Unable to create buffer handle");
+      return 1;
+    }
+  }
+
+  if (!dirtied_) {
+    return 0;
+  }
+  dirtied_ = false;
+
+  // pass dirty regions?
+  return InvalidateRegion(memory_range_);
+}
+
+IndexBufferResource::IndexBufferResource(const MemoryRange& memory_range,
+                                         const Info& info)
+    : BufferResource(memory_range),
+      info_(info) {
+}
+
+IndexBufferResource::~IndexBufferResource() = default;
+
+VertexBufferResource::VertexBufferResource(const MemoryRange& memory_range,
+                                          const Info& info)
+    : BufferResource(memory_range),
+      info_(info) {
+}
+
+VertexBufferResource::~VertexBufferResource() = default;