Add missing MSG_PEEK definition for Solaris.
Fixes
@@ -828,6 +828,8 @@ pub const SO_RCVTIMEO: ::c_int = 0x1006;
pub const SO_ERROR: ::c_int = 0x1007;
pub const SO_TYPE: ::c_int = 0x1008;
+pub const MSG_PEEK: ::c_int = 0x2;
+
pub const IFF_LOOPBACK: ::c_int = 0x8;
pub const SHUT_RD: ::c_int = 0;
