Remove WIN32 defines. They never worked.

src/backend/libpq/pqcomm.c

src/backend/libpq/pqpacket.c

src/backend/optimizer/path/costsize.c

src/backend/optimizer/path/xfunc.c

src/backend/parser/parser.c

src/backend/parser/scan.l

src/backend/postmaster/postmaster.c

src/backend/storage/file/fd.c

src/backend/storage/ipc/s_lock.c

src/backend/storage/lmgr/proc.c

src/backend/storage/smgr/md.c

src/backend/tcop/postgres.c

src/backend/utils/adt/date.c

src/backend/utils/adt/filename.c

src/backend/utils/adt/float.c

src/backend/utils/error/elog.c

src/backend/utils/fmgr/dfmgr.c

src/backend/utils/init/findbe.c

src/backend/utils/init/miscinit.c

src/backend/utils/init/postinit.c