[Bug target/61837] missed loop invariant expression optimization

[wschmidt at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61837

--- Comment #2 from Bill Schmidt <wschmidt at gcc dot gnu.org> ---
Also needs to hoist the "addi 8,4,-1" out to permit this.  That instruction is
also invariant.