port-macppc/54838: macppc cc stopped working

[gson%gson.org@localhost (Andreas Gustafsson)]

>Number:         54838
>Category:       port-macppc
>Synopsis:       macppc cc stopped working
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    port-macppc-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Jan 06 12:05:00 +0000 2020
>Originator:     Andreas Gustafsson
>Release:        NetBSD-current
>Organization:
>Environment:
System: NetBSD
Architecture: macppc
Machine: macppc
>Description:

The C compiler on macppc now segfaults trying to compile even a trivial
program:

  # >test.c
  # cc test.c
  <built-in>: internal compiler error: Segmentation fault
  no stack trace because unwind library not available
  Please submit a full bug report,
  with preprocessed source if appropriate.
  See <http://www.NetBSD.org/support/send-pr.html> for instructions.

This is causing a large number of ATF tests to fail, for example
usr.bin/cc/t_hello:hello.

The problem appeared some time between source dates 2019.12.09.00.15.11
and 2019.12.18.20.38.14.

Logs:

  http://www.netbsd.org/~martin/macppc-atf/8_atf.html#usr.bin_cc_t_hello_hello

  http://www.gson.org/netbsd/bugs/build/macppc/commits-2019.12.html#2019.12.18.20.38.14

>How-To-Repeat:

>Fix: