Condition was apparently reversed so GRUB assumed all devices were
files. This later made it skip BLKFLSBUF ioctl on Linux which caused
various page cache coherency issues. Observed were

- failure to validate blocklist install (read content did not match
  just written)

- failure to detect Linux MD on disk after online hot addition
  (GRUB got stale superblock)

Closes: 46691

Use it to add custom files, so that tests which need them work.

So that we can use it in grub-emu as well as utils.

grub-macbless calls grub_util_biosdisk_init with NULL device.map.

_BSD_SOURCE was added to allow the use of DT_DIR, but that was removed
in e768b770.  While adding
_DEFAULT_SOURCE as well works around problems with current glibc,
neither is in fact needed nowadays.

canonicalize_file_name clashed with gnulib function. Additionally
it was declared in 2 places: emu/misc.h and util/misc.h. Added
grub_ prefix and removed second declaration.

Fixes compile of arm64-emu.

* grub-core/kern/emu/hostfs.c: squahes below warning
  warning: #warning "_BSD_SOURCE and _SVID_SOURCE are deprecated, use _DEFAULT_SOURCE"
Signed-off-by: Khem Raj <raj.khem@gmail.com>

Upstream-Status: Submitted

Fixes compilation on mingw32, where include is apparently missing.

	on ia64 as __clear_cache is a dummy on ia64.

	compilation with GCC <= 4.2.
	* grub-core/kern/emu/argp_common.c: Likewise.

	Move more code to common dl.c. Add missing veneers for arm and arm64.
	Decreases kernel size by 70 bytes on i386-pc (40-50 compressed)

	do essentially the same thing, do it in similar way.

	the function of these files exceeds what can be sanely handled in shell
	in posix-comaptible way. Also writing it in C extends the functionality
	to non-UNIX-like OS and minimal environments.

	Reported by: Glenn Washburn.

	XEN PV environment and load kernels.

	reading large extents and decrease amount of blocklist hook calls.

	and grub_hostfs_init.

	windows method on other platforms without good stat as well.

	use OS-dependent versions rather than to rely on stat().

	closedir to handle filename charset translation.

	* grub-core/Makefile.core.def (kernel): Don't add error.c and progname.c
	explicitly as it's already in libgnu.a.

	fseeko.

	* grub-core/kern/emu/main.c: Add missing include.
	* grub-core/osdep/basic/init.c (grub_util_host_init) [!GRUB_UTIL]:
	Don't call grub_util_init_nls.
	* grub-core/osdep/windows/init.c (grub_util_host_init) [!GRUB_UTIL]:
	Likewise.