[Bug c/81980] Spurious -Wmissing-format-attribute warning in 32-bit mode

[sgunderson at bigfoot dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81980

--- Comment #1 from sgunderson at bigfoot dot com ---
Forgot to say: Also present in trunk r251306 and all the way back to at least
4.8.