[Bug target/81348] PowerPC64: Code built with -mcpu=power9 hits SEGV in RTL split2

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81348

--- Comment #2 from Michael Meissner <meissner at gcc dot gnu.org> ---
Created attachment 41696
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=41696&action=edit
Proposed patch to fix the problem