[PR126816] Fix use-after-free of charlen from rejected trial

Committed as simple and obvious.

Regards,

Jerry

The master branch has been updated by Jerry DeLisle <[email protected]>:

https://gcc.gnu.org/g:0a59650d1ec84d0e155670ef5ae226e4c59ba748

commit r17-3389-g0a59650d1ec84d0e155670ef5ae226e4c59ba748
Author: Jerry DeLisle <[email protected]>
Date:   Tue Aug 18 09:46:21 2026 -0700

     fortran: [PR126816] Fix use-after-free of charlen from rejected trial

     restore_old_symbol reverted only ts.type/ts.kind when undoing a
     tentative symbol change, leaving ts.u.cl pointing at whatever
     charlen the rejected trial had allocated via gfc_set_default_type.
     Restore the whole typespec instead.

             PR fortran/126816

     gcc/fortran/ChangeLog:

             * symbol.cc (restore_old_symbol): Restore the whole typespec
             instead of just type and kind.