pgsql: Enable compiling with the mingw-w64 32 bit compiler.

Enable compiling with the mingw-w64 32 bit compiler.

Original patch by Lars Kanis, reviewed by Nishiyama Tomoaki and tweaked some by me.

This compiler, or at least the latest version of it, is currently broken, and
only passes the regression tests if built with -O0.

Branch
------
master

Details
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http://git.postgresql.org/pg/commitdiff/1a0c76c32fe470142d3663dd84ac960d75a4e8db

Modified Files
--------------
config/ac_func_accept_argtypes.m4 | 2 +-
configure | 159 +++++++++++++++++++++++++++++++++++-
configure.in | 7 ++-
src/include/c.h | 3 +-
src/include/pg_config.h.in | 3 +
src/include/port/win32.h | 26 ++++++-
src/interfaces/ecpg/test/resultmap | 3 +
src/interfaces/libpq/win32.h | 6 ++
src/port/getaddrinfo.c | 4 +-
src/test/regress/resultmap | 3 +
10 files changed, 207 insertions(+), 9 deletions(-)