lib/libsys/sigaction.2: Remove list of signals and refer to siginfo(3) instead.
lib/libsys/sigaction.2: Add reference to siginfo(3) in EXAMPLES
lib/libsys/sigaction.2: Remove Tn macros for mandoc -Tlint warnings
From the original PR:
The Linux sigaction(2) man page provides a detailed and useful enumeration
of possible si_code values (e.g., SI_*, ILL_*, FPE_*, etc), whereas the FreeBSD
man page does not. It would be quite useful if the FreeBSD man page
were extended to document this information.
PR:217892