Move IOFile to a separate file

Reduces the number of files that need to be recompiled
when making changes to FileUtil.h.

Source/Core/VideoBackends/OGL/ProgramShaderCache.cpp

@@ -9,6 +9,7 @@
 
 #include "Common/Align.h"
 #include "Common/CommonTypes.h"
+#include "Common/FileUtil.h"
 #include "Common/Logging/Log.h"
 #include "Common/MsgHandler.h"
 #include "Common/StringUtil.h"