Re-add getopt.h check, remove NT-specific tests for it.

src/backend/bootstrap/bootstrap.c

src/backend/postmaster/postmaster.c

src/backend/tcop/postgres.c

src/backend/utils/mb/common.c

src/bin/pg_dump/pg_dump.c

src/bin/pg_id/pg_id.c

src/bin/psql/psql.c

src/configure.in

src/include/config.h.in

src/include/port/win32.h

src/interfaces/ecpg/preproc/ecpg.c

src/interfaces/libpq/fe-auth.c

src/interfaces/libpq/fe-connect.c

src/interfaces/libpq/fe-exec.c

src/interfaces/libpq/fe-lobj.c

src/interfaces/libpq/fe-misc.c

src/interfaces/libpq/fe-print.c

src/interfaces/libpq/win32.h