sys-fs/erofs-utils: user-space utilities for erofs

New package, taken from https://bugs.gentoo.org/701284
Added metadata.xml.

Package-Manager: Portage-3.0.9, Repoman-3.0.2
Signed-off-by: Denis Reva <denis7774@gmail.com>

sys-fs/erofs-utils/metadata.xml

@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE pkgmetadata SYSTEM 'http://www.gentoo.org/dtd/metadata.dtd'>
+<pkgmetadata>
+	<maintainer type="person">
+		<email>denis7774@gmail.com</email>
+		<name>Denis Reva</name>
+		<description>Partial maintainer</description>
+	</maintainer>
+	<longdescription lang="en">
+		erofs-utils
+		===========
+		erofs-utils includes user-space tools for erofs filesystem images.
+		Currently only mkfs.erofs is available.
+		
+		Mkfs.erofs
+		----------
+		It can create 2 primary kinds of erofs images: (un)compressed.
+		- For compressed images, it's able to use several compression algorithms, but lz4(hc) are only supported due to the current linux kernel implementation.
+		- For uncompressed images, it can decide whether the last page of a file should be inlined or not properly [1].
+		How to generate erofs images
+		~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+		Currently lz4 and lz4hc are available for compression, e.g.
+		$ mkfs.erofs -zlz4hc foo.erofs.img foo/
+		Or leave all files uncompressed as a option:
+		$ mkfs.erofs foo.erofs.img foo/
+		
+		Known issues
+		~~~~~~~~~~~~
+		1. LZ4HC cannot compress long zeroed buffer properly with
+		LZ4_compress_HC_destSize()
+		https://github.com/lz4/lz4/issues/784
+	</longdescription>
+	<use>
+		<flag name="uuid">Allow interaction with libuuid in sys-apps/util-linux. It's recommended turn on</flag>
+	</use>
+</pkgmetadata>