[Bug target/127256] [16 regression] libjxl build ICEs in simplify_gen_subreg_concatn, at lower-subreg.cc:744

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127256

--- Comment #7 from Drea Pinski <pinskia at gcc dot gnu.org> ---
Created attachment 65526
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=65526&action=edit
Cleaned up reduced testcase

This one does not have undefined behaviors in it either.