Add missing network declaration for Solaris.

These are required to compile std.socket.
Add more Solaris declarations.

Add missing declations in `core.sys.posix.utime` and `core.sys.posix.utime`.
Merge pull request #1035 from redstar/solaris_net

Add missing network declaration for Solaris.
Merge pull request #1036 from redstar/solaris2

Add more Solaris declarations.