[Bug c/66663] gcc misses optimization emits useless test of (a & 31) with 32

[fuz at fuz dot su]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66663

--- Comment #1 from Robert Clausecker <fuz at fuz dot su> ---
Sorry. I meant to say: The branch will always be taken, not never.