[Bug target/127306] RISC-V bclr_lowest_set_bit pass produces wrong code

[uwu at icenowy dot me via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127306

--- Comment #2 from Icenowy Zheng <uwu at icenowy dot me> ---
Yes, it should be the same, but Yuechi's patch seems to be not enough.