Port mode_t (and gid_t, uid_t) to MS-Windows

Problem reported by Manuela Friedrich in:
* zic.c (gid_t, mode_t, uid_t) [HAVE_DIRECT_H]: New typedefs.
(gid_t, mode_t, uid_t): Remove these macros.

Author: eggert

Makefile

@@ -269,7 +269,7 @@ LDLIBS=
 #	variables like 'tzname' required by POSIX
 #  -DHAVE_PWD_H=0 if your system lacks pwd.h, grp.h and corresponding functions
 #	The following additional options may be needed:
-#	-Dgid_t=T, -Duid_t=T to define gid_t, uid_t to be type T (default int)
+#	-Dgid_t=T, -Duid_t=T to define gid_t, uid_t to be type T
 #  -DHAVE_SETENV=0 if your system lacks the setenv function
 #  -DHAVE_SETMODE=[01] if your system lacks or has the setmode and getmode
 #	functions (default is guessed)
@@ -286,7 +286,7 @@ LDLIBS=
 #  -DHAVE_SYMLINK=0 if your system lacks the symlink function
 #  -DHAVE_SYS_STAT_H=0 if <sys/stat.h> does not work*
 #	The following additional option may be needed:
-#	-Dmode_t=T to define mode_t to be type T (default int)
+#	-Dmode_t=T to define mode_t to be type T
 #  -DHAVE_TZSET=0 if your system lacks a tzset function
 #  -DHAVE_UNISTD_H=0 if <unistd.h> does not work*
 #  -DHAVE_UTMPX_H=0 if <utmpx.h> does not work*

zic.c

@@ -49,6 +49,7 @@ enum { FORMAT_LEN_GROWTH_BOUND = 5 };
 # include <direct.h>
 # include <io.h>
 # define mkdir(name, mode) _mkdir(name)
+typedef unsigned short gid_t, mode_t, uid_t;
 #endif
 
 #ifndef HAVE_GETRANDOM
@@ -67,10 +68,6 @@ enum { FORMAT_LEN_GROWTH_BOUND = 5 };
 
 #if HAVE_SYS_STAT_H
 # include <sys/stat.h>
-#else
-# ifndef mode_t
-#  define mode_t int
-# endif
 #endif
 
 #ifndef S_IRWXU
@@ -119,12 +116,6 @@ static mode_t creat_perms = CREAT_PERMS;
 # include <grp.h>
 # include <pwd.h>
 #else
-# ifndef gid_t
-#  define gid_t int
-# endif
-# ifndef uid_t
-#  define uid_t int
-# endif
 struct group { gid_t gr_gid; };
 struct passwd { uid_t pw_uid; };
 # define getgrnam(arg) NULL