re PR libstdc++/64367 (g++-v5/stdexcept:52:28: error: invalid use of non-static data member '_M_p')

	PR libstdc++/64367
	* include/std/stdexcept: Don't use non-static member in sizeof.

From-SVN: r218997

libstdc++-v3/ChangeLog

+2014-12-21  Jonathan Wakely  <jwakely@redhat.com>
+
+	PR libstdc++/64367
+	* include/std/stdexcept: Don't use non-static member in sizeof.
+
 2014-12-20  François Dumont  <fdumont@gcc.gnu.org>
 
 	* include/debug/vector (std::__debug::vector<>::clear()): Do not reset

libstdc++-v3/include/std/stdexcept

@@ -49,7 +49,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   {
     union {
       const char* _M_p;
-      char _M_bytes[sizeof(_M_p)];
+      char _M_bytes[sizeof(const char*)];
     };
 
     __cow_string();