https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94044
--- Comment #2 from Kito Cheng <kito at gcc dot gnu.org> --- I saw PR94027 before open this bug, it happened since same commit, I tested on x86, x86_64, riscv32, riscv64, aarch64, arm, nds32le, mips, mips64, but only riscv64 and arm fail on this testcase, and only ICE when -std=c++14, no ICE with -std=gnu++14 or -std=c++11 or -std=gnu++11. so I decide to open a new one :)
