[Bug target/88343] [7/8/9 Regression] R31 is unconditionally saved/restored on powerpc-darwin even when it's not necessary.

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88343

--- Comment #7 from Iain Sandoe <iains at gcc dot gnu.org> ---
so, fixed on trunk so far.