Bug in GNAT.Socket.Check_Selector in GNAT 3.14 Linux runtime

[frederic.ormancey@atosorigin.com (Frédéric Ormancey)]

Hi!

While implementing a socket interface on Linux platform, I find a
major bug in GNAT.Socket package : the Check_Selector procedure
doesn't check the return status of the C_Select routine, and don't
convert correctly the TimeOut duration value to TimeVal C Structure =>
The result is an immediate return of the Check_Selector procedure,
with invalid flags in socket set's.

I correct the timeout conversion ( when construct the C TimeVal
structure, use a float'floor instead of an integer cast to take the
first integer smaller than the duration timeout instead of the rounded
integer value of the duration timeout )

I post the correction to reports@gnat.com, with some other procedure
added in GNAT.Socket package :

Service structure access, like host structure access :
   type Serv_Entry_Type (Aliases_Length : Natural) is private;
   function Get_Service_By_Name
   function Get_Service_By_Port

Byte order conversion :
   function Short_To_Network, Network_To_Short, Long_To_Network,
Network_To_Long