[Bug target/95730] GCN offloading ICEs after commit fe7ebef7fe4f9acb79658ed9db0749b07efc3105 "Add support for __builtin_bswap128"

[ams at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95730

--- Comment #4 from Andrew Stubbs <ams at gcc dot gnu.org> ---
In fact default_scalar_mode_supported_p does return *false* for TImode (because
LONG_LONG_TYPE_SIZE == 64, and BITS_PER_WORD == 32).

Therefore int128_t does not exist, as far as users are concerned. I'm not sure
how that translates to the GCC internals, but trying to use TImode for anything
other than moves is not going to work on GCN.