Fix specs for Socket.pack_sockaddr_in

Author: andrykonchin

lib/truffle/socket/truffle/foreign.rb

@@ -266,11 +266,15 @@ def self.pack_sockaddr_in(host, port, family = ::Socket::AF_UNSPEC,
             # to succeed on some platforms (most notably, Solaris).
             Integer(port)
             type = ::Socket::SOCK_DGRAM
-          rescue ArgumentError
+          rescue ArgumentError, TypeError
             # Ignored.
           end
         end
 
+        if Primitive.nil?(port)
+          port = 0
+        end
+
         hints = Addrinfo.new
 
         hints[:ai_family]   = family

spec/ruby/library/socket/socket/pack_sockaddr_in_spec.rb

@@ -2,6 +2,6 @@
 require_relative '../fixtures/classes'
 require_relative '../shared/pack_sockaddr'
 
-describe "Socket#pack_sockaddr_in" do
+describe "Socket.pack_sockaddr_in" do
   it_behaves_like :socket_pack_sockaddr_in, :pack_sockaddr_in
 end