[Bug libstdc++/69881] with gcc-6 of today building gcc-4.9 fails

[bernd.edlinger at hotmail dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69881

--- Comment #6 from Bernd Edlinger <bernd.edlinger at hotmail dot de> ---
(In reply to Jonathan Wakely from comment #4)
> The patch seems wrong, your new sections don't add anything to namespace std.

yes.  I think probably cstddef is free to ignore __need_size_t. right?

Then it would be better to #undef all of them, just in case.

cat test.cc
#define __need_size_t
#include <cstddef>

gcc -c test.cc
In file included from test.cc:2:0:
/home/ed/gnu/install/include/c++/6.0.0/cstddef:51:11: error: '::max_align_t'
has not been declared
   using ::max_align_t;
           ^~~~~~~~~~~