fflush_unlocked is currently desired in ports by sysutils/metalog, and redefined as the locked fflush.
fputc_unlocked, fputs_unlocked, fread_unlocked, and fwrite_unlocked are currently desired in ports by devel/elfutils, and redefined as the locked fputs, fread, and fwrite respectively.
Nothing currently wants fputc_unlocked, but if we're doing fputs_unlocked then fputc_unlocked is sensible as it's likely to be used for optimizing repeated fputc.
Macros provided for those with pure-libc implementations rather than inline implementations for easy transition into this state where we start providing them. PRs have been submitted for the two ports that currently #define theseand fwrite respectively.