[PATCH] PostgreSQL fails to build with 32bit MinGW-w64

Hi PostgreSQL hackers,

support for Mingw-w64 compiler was added to postgres with commit 91812df.
Unfortunately only the 64 bit output is working right now. This issue was
already highlighted with initial patch in
http://archives.postgresql.org/pgsql-bugs/2011-07/msg00059.php

Mingw-w64 uses the same header files for 32 and 64 bit compiles. So the same
conditions apply to mingw-w32 bit as for the WIN64 case. In WIN64 "WSAAPI" is
defined to nothing, but in 32 bit to stdcall, so it needs to be used in the
accept-parameter check, too. Maybe you prefer PASCAL instead of WSAAPI in
configure.

I tested successful compilation for the following platforms:
- i686-w64-mingw32 - gcc v4.6.1
- x86_64-w64-mingw32 - gcc v4.6.1
- i586-mingw32msvc - gcc v4.4.4
- x86_64-linux-gnu - gcc v4.6.1

--
Kind regards,
Lars Kanis