[Bug target/79079] [6/7] Wrong code gen for __builtin_mul_overflow when TRULY_NOOP_TRUNCATION (32, 64) == false

[npickito at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79079

--- Comment #3 from Kito Cheng <npickito at gmail dot com> ---
Hi Jakub:

Thank your review, your are right, I might change all gen_lowpart to
convert_modes to deal with all other TRULY_NOOP_TRUNCATION == false case, in
RISC-V and MIPS64 only TRULY_NOOP_TRUNCATION(64, 32) is false so only one
modification is enough but it's still potential bug here.

I will update the patch, re-run testsuite and post to gcc-patch mailing list,
thanks again :)