[Bug target/55023] hppa: wrong code generated with tail call optimisation

[law at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55023

--- Comment #10 from Jeffrey A. Law <law at redhat dot com> ---
IIRC, the PA was a bit unique in how we had to set up the virtual registers due
to the combination of stack growth and arg growth directions.  It may be the
case that after virtual register instantiation we're left with something
different than is seen on any other architecture.  Thus the potential oversight
in DSE's handling of argument setup, particularly with sibcalls which use the
parent's stack.

But that's just speculation based on knowledge from 2 decades ago...  Take it
with a grain of salt...