[patch] implement LWG 2144

[Jonathan Wakely]

        * include/std/typeindex (type_index::name()): LWG 2144: Add noexcept.

Tested x86_64-linux, committed to trunk, can also go on the 4.8 branch
when it opens.

diff --git a/libstdc++-v3/include/std/typeindex 
b/libstdc++-v3/include/std/typeindex
index 9e6db30..15be751 100644
--- a/libstdc++-v3/include/std/typeindex
+++ b/libstdc++-v3/include/std/typeindex
@@ -83,7 +83,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     { return _M_target->hash_code(); }
 
     const char*
-    name() const
+    name() const noexcept
     { return _M_target->name(); }
 
   private: