[Bug target/91683] ICE: SIGSEGV at -O when compiling for riscv64

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91683

--- Comment #9 from Segher Boessenkool <segher at gcc dot gnu.org> ---
So when was the array reallocated?  combine does in general rely on all
rtxen to stay in place, etc.