loader: Add xzfs support by defualt to BIOS and EFI loaders

For the BIOS, add xzfs support. This is a tiny increase in the loader
size, but allows us to fetch compressed files from any of the
filesystems we support, including over the network.

For EFI, also add gzipfs and bzip2fs support we well. The increment for
these files is tiny.

Sponsored by:		Netflix

stand/efi/loader/Makefile

@@ -3,6 +3,9 @@ LOADER_MSDOS_SUPPORT?=	yes
 LOADER_UFS_SUPPORT?=	yes
 LOADER_CD9660_SUPPORT?=	no
 LOADER_EXT2FS_SUPPORT?=	no
+LOADER_GZ_SUPPORT?=     yes
+LOADER_BZIP2_SUPPORT?=  yes
+LOADER_XZ_SUPPORT?=     yes
 
 .include <bsd.init.mk>
 

stand/i386/loader/Makefile

@@ -9,6 +9,7 @@ LOADER_MSDOS_SUPPORT?=	no
 LOADER_UFS_SUPPORT?=	yes
 LOADER_GZIP_SUPPORT?=	yes
 LOADER_BZIP2_SUPPORT?=	yes
+LOADER_XZ_SUPPORT?=	yes
 
 .include <bsd.init.mk>
 
@@ -32,12 +33,12 @@ VERSION_FILE?=	${.CURDIR}/../loader/version
 #
 # will tell you how many kiB of lomem are available.
 #
-# We further reduce this to 500k, though, to give PXE an additional 64k of space
+# We further reduce this to 505k, though, to give PXE an additional 64k of space
 # so pxeloader will fit. If you have special needs that do not include pxeboot,
 # you can safely set this as high as 560000 generally, or a bit higher if you
 # have tight control over the machines you are booting on.
 #
-LOADERSIZE?=	500000		# Largest known safe size for loader.bin
+LOADERSIZE?=	505000		# Largest known safe size for loader.bin
 
 .PATH:		${BOOTSRC}/i386/loader