[Bug target/112651] RISC-V Vector new option -mvect-lmul required to force LMUL values (rather than --param=riscv-autovec-lmul to hint at values)

[juzhe.zhong at rivai dot ai via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112651

--- Comment #5 from JuzheZhong <juzhe.zhong at rivai dot ai> ---
I guess it's more reasonable to have -mrvv-vector-lmul like we will have
-mrvv-vector-bits.

the option can be m1/m2/m4/m8/dynamic.