[Bug preprocessor/92919] invalid memory access in wide_str_to_charconst when running ucn2.C testcase (caught by hwasan)

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92919

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2019-12-13
           Assignee|unassigned at gcc dot gnu.org      |jakub at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 47486
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=47486&action=edit
gcc10-pr92919.patch

Untested fix.