[Bug target/123010] RV64: 32-bit multiply by 2 generates slli+srai+slli and doesn't use slliw or addw

[camel-cdr at protonmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123010

--- Comment #4 from camel-cdr <camel-cdr at protonmail dot com> ---
I don't really see how this would be a parameter/return value thing,
considering the multiply by 3 does use addw.