Starting to remove windows.h includes from things.

src/xenia/apu/audio_system.h

@@ -17,6 +17,8 @@
 #include "xenia/emulator.h"
 #include "xenia/xbox.h"
 
+typedef void* HANDLE;
+
 namespace xe {
 namespace kernel {
 class XHostThread;

src/xenia/apu/xaudio2/xaudio2_audio_driver.cc

@@ -9,6 +9,8 @@
 
 #include "xenia/apu/xaudio2/xaudio2_audio_driver.h"
 
+// Must be included before xaudio2.h so we get the right windows.h include.
+#include "xenia/base/platform_win.h"
 #include <xaudio2.h>
 
 #include "xenia/apu/apu_flags.h"