[Bug target/77676] powerpc64 and powerpc64le stage2 bootstrap fail

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77676

--- Comment #10 from Martin Sebor <msebor at gcc dot gnu.org> ---
Created attachment 39670
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=39670&action=edit
Patch under test.

The patch should resolve all the issues discussed in this bug.  I don't have
access to Darwin so I'd appreciate your help validating it there.  The patch
doesn't enable the optimization yet.  I'm testing with it enabled and assuming
good results and no objections I'll re-enable it when I commit it.