Provide a 'mach_print' symbol in libc.

--- a/sysdeps/mach/hurd/i386/libc.abilist	2020-04-01 19:22:44.710088821 +0200
+++ b/sysdeps/mach/hurd/i386/libc.abilist	2020-04-01 19:22:52.062051161 +0200
@@ -338,6 +338,7 @@
 GLIBC_2.2.6 __mach_port_allocate F
 GLIBC_2.2.6 __mach_port_deallocate F
 GLIBC_2.2.6 __mach_port_insert_right F
+GLIBC_2.21 __mach_print F
 GLIBC_2.2.6 __mach_reply_port F
 GLIBC_2.2.6 __mach_task_self_ D 0x4
 GLIBC_2.2.6 __mach_thread_self F

--- a/mach/Versions
+++ b/mach/Versions
@@ -56,6 +56,7 @@
   }
   GLIBC_2.21 {
     __mach_host_self_;
+    mach_print;
   }
 
   HURD_CTHREADS_0.3 {
ndex</a> : <a href='/guix/'>guix</a></td><td class='form'><form method='get'>
<input type='hidden' name='id' value='8d1ab36a56b4fda3f89c81816cb25729ba95176d'/><select name='h' onchange='this.form.submit();'>
<option value='koszko' selected='selected'>koszko</option>
<option value='koszko-scripts'>koszko-scripts</option>
</select> <input type='submit' value='switch'/></form></td></tr>
<tr><td class='sub'>Wojtek's customized Guix</td><td class='sub right'></td></tr></table>
<table class='tabs'><tr><td>
<a href='/guix/about/'>about</a><a href='/guix/'>summary</a><a href='/guix/refs/?id=8d1ab36a56b4fda3f89c81816cb25729ba95176d'>refs</a><a class='active' href='/guix/log/gnu/packages/patches/libnftnl-dont-check-NFTNL_FLOWTABLE_SIZE.patch'>log</a><a href='/guix/tree/gnu/packages/patches/libnftnl-dont-check-NFTNL_FLOWTABLE_SIZE.patch?id=8d1ab36a56b4fda3f89c81816cb25729ba95176d'>tree</a><a href='/guix/commit/gnu/packages/patches/libnftnl-dont-check-NFTNL_FLOWTABLE_SIZE.patch?id=8d1ab36a56b4fda3f89c81816cb25729ba95176d'>commit</a><a href='/guix/diff/gnu/packages/patches/libnftnl-dont-check-NFTNL_FLOWTABLE_SIZE.patch?id=8d1ab36a56b4fda3f89c81816cb25729ba95176d'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/packages/patches/libnftnl-dont-check-NFTNL_FLOWTABLE_SIZE.patch'>
<input type='hidden' name='id' value='8d1ab36a56b4fda3f89c81816cb25729ba95176d'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=8d1ab36a56b4fda3f89c81816cb25729ba95176d'>root</a>/<a href='/guix/log/gnu?id=8d1ab36a56b4fda3f89c81816cb25729ba95176d'>gnu</a>/<a href='/guix/log/gnu/packages?id=8d1ab36a56b4fda3f89c81816cb25729ba95176d'>packages</a>/<a href='/guix/log/gnu/packages/patches?id=8d1ab36a56b4fda3f89c81816cb25729ba95176d'>patches</a>/<a href='/guix/log/gnu/packages/patches/libnftnl-dont-check-NFTNL_FLOWTABLE_SIZE.patch?id=8d1ab36a56b4fda3f89c81816cb25729ba95176d'>libnftnl-dont-check-NFTNL_FLOWTABLE_SIZE.patch</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/packages/patches/libnftnl-dont-check-NFTNL_FLOWTABLE_SIZE.patch?id=8d1ab36a56b4fda3f89c81816cb25729ba95176d&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2019-12-12 03:02:31 +0100'>2019-12-12</span></td><td><a href='/guix/commit/gnu/packages/patches/libnftnl-dont-check-NFTNL_FLOWTABLE_SIZE.patch?id=79a392535591fc4224280ade6a87910793ca6688'>gnu: libnftnl: Update to 1.1.5.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/linux.scm (libnftnl): Update to 1.1.5.
[source]: Add patch.
* gnu/packages/patches/libnftnl-dont-check-NFTNL_FLOWTABLE_SIZE.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>