Revert "Remove some unnecessary includes."

Turns out this explodes on Linux.

This reverts commit c4696568cc.

Source/Core/AudioCommon/Src/NullSoundStream.h

@@ -6,6 +6,7 @@
 #define _NULLSOUNDSTREAM_H_
 
 #include "SoundStream.h"
+#include "Thread.h"
 
 #define BUF_SIZE (48000 * 4 / 32)
 

Source/Core/Common/Src/DebugInterface.h

@@ -2,6 +2,7 @@
 #define _DEBUGINTERFACE_H
 
 #include <string>
+#include <string.h>
 
 class DebugInterface
 {

Source/Core/Core/Src/HW/EXI_Device.h

@@ -5,6 +5,7 @@
 #ifndef _EXIDEVICE_H
 #define _EXIDEVICE_H
 
+#include "Common.h"
 #include "ChunkFile.h"
 
 enum TEXIDevices

Source/Core/InputCommon/Src/GCPadStatus.h

@@ -5,6 +5,8 @@
 #ifndef _GCPAD_H_INCLUDED__
 #define _GCPAD_H_INCLUDED__
 
+#include "CommonTypes.h"
+
 #define PAD_ERR_NONE            0
 #define PAD_ERR_NO_CONTROLLER   -1
 #define PAD_ERR_NOT_READY       -2