posix.zig: export sigset_t and matching operations from system
Unify the C library sigset_t and Linux native sigset_t and the accessor
operations.
Add tests that the various sigset_t operations are working. And clean up
existing tests a bit.
d16079d79aPat Tullmann committed on 5/1/2025, 3:32:04 AMparent298b188