[patch c++]: Fix PR/53904

[H.J. Lu]

On Wed, Nov 26, 2014 at 9:52 AM, Kai Tietz <ktietz70@googlemail.com> wrote:
> Ok.  Adjusted patch attached.  Nevertheless we should use here
> unsigned HWI instead of possible truncation to signed int.  I admit
> that it is unlikely to have more then 2^31 elements, but well ....
>
> Ok for apply with adjusted ChangeLog?
>
> Regards,
> Kai
>

On Linux/x86, the testcase fails with

output is:
/export/gnu/import/git/gcc/gcc/testsuite/g++.dg/cpp0x/pr63904.C: In
instantiation of 'struct foo<0>':^M
/export/gnu/import/git/gcc/gcc/testsuite/g++.dg/cpp0x/pr63904.C:10:26:
  required from here^M
/export/gnu/import/git/gcc/gcc/testsuite/g++.dg/cpp0x/pr63904.C:6:12:
error: ISO C++ forbids zero-size array [-Wpedantic]^M

FAIL: g++.dg/cpp0x/pr63904.C  -std=c++11 (test for excess errors)

H.J.