commit 7019fbe103165b9b26a9391d5ecd4c7fcb6f3ec9 and commit e709a6f07ade208ba513f9225222336f30c304b0 misspelled bits/alltypes.h.
previously, only a few archs defined it here. this change makes the presence consistent across all archs, and reduces the amount of header duplication (and potential for future inconsistency) between archs.