Add initial support for *-*-nacl target.

include/llvm/ADT/Triple.h

 //===-- llvm/ADT/Triple.h - Target triple helper class ----------*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_ADT_TRIPLE_H
@@ skipping 78 matching lines @@
     Lv2,        // PS3
     MacOSX,
     MinGW32,    // i*86-pc-mingw32, *-w64-mingw32
     NetBSD,
     OpenBSD,
     Psp,
     Solaris,
     Win32,
     Haiku,
     Minix,
-    RTEMS
+    RTEMS,
+    NativeClient
   };
   enum EnvironmentType {
     UnknownEnvironment,
 
     GNU,
     GNUEABI,
     EABI,
     MachO
   };
 
@@ skipping 270 matching lines @@
   /// arch(3)).
   static ArchType getArchTypeForDarwinArchName(StringRef Str);
 
   /// @}
 };
 
 } // End llvm namespace
 
 
 #endif