[Bug target/71709] powerpc64le: argument to strcpy() optimised out

[amodra at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71709

--- Comment #5 from Alan Modra <amodra at gmail dot com> ---
Created attachment 38802
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=38802&action=edit
fix

Cures the error in find_call_crossed_cheap_reg