[patch, committed] Fix PR 84640

[Thomas Koenig]

Hi,

I just committed the fix below as obvious and simple. No test case
because the problem was only visible in with an instrumented
compiler.

Regards

Thomas

2018-10-06 Thomas Koenig <***@gcc.gnu.org>

PR fortran/84640
* simplify.c (gfc_simplify_cshift): Extend size of hs_ex and ss_ex
by one. Set extents one past the array boundaries to zero to avoid
warning with instrumented compiler.
(gfc_simplify_eoshift): Likewise, only for ss_ex.