Get rid of OS(AIX)

Source/wtf/Platform.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2007-2009 Torch Mobile, Inc.
  * Copyright (C) 2010, 2011 Research In Motion Limited. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 257 matching lines @@
 #endif /* ARM */
 
 /* ==== OS() - underlying operating system; only to be used for mandated low-level services like 
    virtual memory, not to choose a GUI toolkit ==== */
 
 /* OS(ANDROID) - Android */
 #ifdef ANDROID
 #define WTF_OS_ANDROID 1
 #endif
 
-/* OS(AIX) - AIX */
-#ifdef _AIX
-#define WTF_OS_AIX 1
-#endif
-
 /* OS(DARWIN) - Any Darwin-based OS, including Mac OS X and iPhone OS */
 #ifdef __APPLE__
 #define WTF_OS_DARWIN 1
 
 #include <Availability.h>
 #include <AvailabilityMacros.h>
 #include <TargetConditionals.h>
 #endif
 
 /* OS(FREEBSD) - FreeBSD */
@@ skipping 25 matching lines @@
 #if defined(sun) || defined(__sun)
 #define WTF_OS_SOLARIS 1
 #endif
 
 /* OS(WINDOWS) - Any version of Windows */
 #if defined(WIN32) || defined(_WIN32)
 #define WTF_OS_WINDOWS 1
 #endif
 
 /* OS(UNIX) - Any Unix-like system */
-#if   OS(AIX)              \
-    || OS(ANDROID)          \
+#if OS(ANDROID)          \
     || OS(DARWIN)           \
     || OS(FREEBSD)          \
     || OS(HURD)             \
     || OS(LINUX)            \
     || OS(NETBSD)           \
     || OS(OPENBSD)          \
     || OS(SOLARIS)          \
     || defined(unix)        \
     || defined(__unix)      \
     || defined(__unix__)
@@ skipping 80 matching lines @@
 
 #if !defined(ENABLE_THREADING_LIBDISPATCH) && HAVE(DISPATCH_H)
 #define ENABLE_THREADING_LIBDISPATCH 1
 #elif !defined(ENABLE_THREADING_OPENMP) && defined(_OPENMP)
 #define ENABLE_THREADING_OPENMP 1
 #elif !defined(THREADING_GENERIC)
 #define ENABLE_THREADING_GENERIC 1
 #endif
 
 #endif /* WTF_Platform_h */