Add initial support for __int128 to Config and TypeTraits

[SVN r81064]

include/boost/config/compiler/gcc.hpp

@@ -146,6 +146,12 @@
 #  endif
 #endif
 
+//
+// Recent GCC versions have __int128 when in 64-bit mode:
+//
+#if defined(__SIZEOF_INT128__)
+#  define BOOST_HAS_INT128
+#endif
 
 // C++0x features in 4.3.n and later
 //

include/boost/config/suffix.hpp

@@ -489,6 +489,18 @@ namespace boost{
 #  endif
 }
 #endif
+// same again for __int128:
+#if defined(BOOST_HAS_INT128) && defined(__cplusplus)
+namespace boost{
+#  ifdef __GNUC__
+   __extension__ typedef __int128 int128_type;
+   __extension__ typedef unsigned __int128 uint128_type;
+#  else
+   typedef __int128 int128_type;
+   typedef unsigned __int128 uint128_type;
+#  endif
+}
+#endif
 
 // BOOST_[APPEND_]EXPLICIT_TEMPLATE_[NON_]TYPE macros --------------------------//
 //