Log Message:
ocaml: fix SmartOS build.

- Claimed shared library support. same as other ELF platforms, but
  since it's not GNU ld, no -Wl,-E available.
- Change the PLIST vars based on what is actually built
- consider x86_64-*-solaris to be x86_64 and solaris. the arch=none
  option doesn't build.
- Search for socket stuff in -lnsl -lsocket.
- for a POSIX prototype sigwait, we need to define _XOPEN_SOURCE to something