Add socket support to platform code....

Add socket support to platform code.

The new Socket class is an encapsulation of the standard BSD socket API. As it depends on platform specific include files and have some slight platform variations it is part of the platform code.

On Mac OS only the option SO_REUSEADDR is set to true for server sockets. Running the test required it as the bound listener socket would sometimes end up in TIME_WAIT. On Windows and Linux this has never been observed (given the client end of the socket is closed before the server end).

The code has been tested on Windows, Linux and Mac OS. The FreeBSD version is a copy of the Linux version but has not been compiled nor tested.

Missing Xcode project updates.

Committed: http://code.google.com/p/v8/source/detail?r=1349

[Søren Thygesen Gjesse, 2009-02-24 10:25:11]

The code for each of the four platforms is almost identical. The differences
are:

initialization is required in Windows

close is closesocket on Windows

option SO_REUSEADDR is set for listener sockets on Mac OS

type is int except on Windows where is is SOCKET (#define of int in header file)

As the code relies on platform header files it needs to be in the platform
files. Adding an #include of a .cc file implementing the commons in class Scoket
instead of derived class <Platform>Scoket might be an option. Then again the
implementation of Thread is also almost identical on Linux, Mac OS and FreeBSD.

I think we should keep separate implementations for now until this is well
tested and the "real" differences have materialized.

[Mads Ager (chromium), 2009-02-24 13:21:04]

LGTM