[Bug target/91289] powerpc-eabi: Usage of -fstack-limit-symbol leads to internal compiler error during RTL pass

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91289

--- Comment #10 from Segher Boessenkool <segher at gcc dot gnu.org> ---
The prologue is not necessarily inserted as the first bb, so it's not clear
to me that CA is never live there.

The code copying r11 to r0, and back, is removed by the usual optimisations
btw, in all normal cases.