Auto merge of #2697 - pfmooney:illumos-siginfo, r=Amanieu
Auto merge of #2697 - pfmooney:illumos-siginfo, r=Amanieu

solarish: Expose siginfo_t data as functions

This will bring illumos (and Solaris) functionality in line with the other UNIX (and UNIX-like) platforms, where unions often hamper access to those data fields.

rust-lang/libc,rust-lang/libc,rust-lang/libc