[Bug target/121845] [Trunk] RISC-V rv64gcv: miscompile at -O0

[law at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121845

--- Comment #3 from Jeffrey A. Law <law at gcc dot gnu.org> ---
I've pushed Robin's patch to the trunk.  What I don't know is whether or not
this likely affects gcc-15, in which case we should add the regressinon marker
and backport in a week or so.

Robin, any sense of whether or not this affects gcc-15?