[Bug target/120807] [15/16 Regression] LoongArch: "ICE: unrecognizable insn" building box64

[xry111 at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120807

--- Comment #5 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
r16-1998.

Will backport if no objection in a few days.