Merge branch 'dm/compat-s-ifmt-for-zos'

Long overdue departure from the assumption that S_IFMT is shared by
everybody made in 2005.

* dm/compat-s-ifmt-for-zos:
  compat: convert modes to use portable file type values

Makefile

@@ -191,6 +191,10 @@ all::
 # Define NO_TRUSTABLE_FILEMODE if your filesystem may claim to support
 # the executable mode bit, but doesn't really do so.
 #
+# Define NEEDS_MODE_TRANSLATION if your OS strays from the typical file type
+# bits in mode values (e.g. z/OS defines I_SFMT to 0xFF000000 as opposed to the
+# usual 0xF000).
+#
 # Define NO_IPV6 if you lack IPv6 support and getaddrinfo().
 #
 # Define NO_UNIX_SOCKETS if your system does not offer unix sockets.
@@ -1230,6 +1234,10 @@ endif
 ifdef NO_TRUSTABLE_FILEMODE
 	BASIC_CFLAGS += -DNO_TRUSTABLE_FILEMODE
 endif
+ifdef NEEDS_MODE_TRANSLATION
+	COMPAT_CFLAGS += -DNEEDS_MODE_TRANSLATION
+	COMPAT_OBJS += compat/stat.o
+endif
 ifdef NO_IPV6
 	BASIC_CFLAGS += -DNO_IPV6
 endif