Minimally patch libtheora's ancient config.guess to support mips64.

--- libtheora/config.guess.orig	2009-02-23 22:50:50.000000000 -0500
+++ libtheora/config.guess	2013-10-31 23:49:48.155999944 -0400
@@ -798,25 +798,24 @@
     m68*:Linux:*:*)
 	echo ${UNAME_MACHINE}-unknown-linux-gnu
 	exit 0 ;;
-    mips:Linux:*:*)
+    mips:Linux:*:* | mips64:Linux:*:*)
 	eval $set_cc_for_build
 	sed 's/^	//' << EOF >$dummy.c
 	#undef CPU
-	#undef mips
-	#undef mipsel
+	#undef ${UNAME_MACHINE}
+	#undef ${UNAME_MACHINE}el
 	#if defined(__MIPSEL__) || defined(__MIPSEL) || defined(_MIPSEL) || defined(MIPSEL)
-	CPU=mipsel
+	CPU=${UNAME_MACHINE}el
 	#else
 	#if defined(__MIPSEB__) || defined(__MIPSEB) || defined(_MIPSEB) || defined(MIPSEB)
-	CPU=mips
+	CPU=${UNAME_MACHINE}
 	#else
 	CPU=
 	#endif
 	#endif
 EOF
-	eval `$CC_FOR_BUILD -E $dummy.c 2>/dev/null | grep ^CPU=`
-	rm -f $dummy.c && rmdir $tmpdir
-	test x"${CPU}" != x && echo "${CPU}-pc-linux-gnu" && exit 0
+	eval `$CC_FOR_BUILD -E $dummy.c 2>/dev/null | grep '^CPU'`
+	test x"${CPU}" != x && { echo "${CPU}-unknown-linux-gnu"; exit 0; }
 	;;
     ppc:Linux:*:*)
 	echo powerpc-unknown-linux-gnu
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<div class='path'>path: <a href='/guix/log/?id=f7d88cd4707eeaf02f9b854f05803d8d0428f670'>root</a>/<a href='/guix/log/tests?id=f7d88cd4707eeaf02f9b854f05803d8d0428f670'>tests</a>/<a href='/guix/log/tests/containers.scm?id=f7d88cd4707eeaf02f9b854f05803d8d0428f670'>containers.scm</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/tests/containers.scm?id=f7d88cd4707eeaf02f9b854f05803d8d0428f670&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-10-01 12:51:13 +0200'>2020-10-01</span></td><td><a href='/guix/commit/tests/containers.scm?id=e74818353882f187e5971b5a3a481f17df883dbe'>linux-container: Reset jailed root permissions.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/build/linux-container.scm (mount-file-systems): Add 'chmod' call.
* tests/containers.scm
("call-with-container, mnt namespace, root permissions"): New test.
</span></span></td><td>Jelle Licht</td></tr>
<tr><td><span title='2019-10-15 10:21:41 +0200'>2019-10-15</span></td><td><a href='/guix/commit/tests/containers.scm?id=e464ac667297d2acf57e52438a39cadc87b95da2'>tests: Skip container test when lacking kernel support.</a><span class='msg-avail'>...<span class='msg-tooltip'>This is a followup to 96b35998e610c7fc37bf87bf9e07e63d3bebd0a3.

* tests/containers.scm ("eval/container, non-empty load path"): Add
missing 'skip-if-unsupported' call.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-09-18 23:08:28 +0200'>2019-09-18</span></td><td><a href='/guix/commit/tests/containers.scm?id=96b35998e610c7fc37bf87bf9e07e63d3bebd0a3'>linux-container: 'eval/container' correctly passes -L and -C flags.</a><span class='msg-avail'>...<span class='msg-tooltip'>This fixes a type error.

* gnu/system/linux-container.scm (eval/container): Use 'append-map', not
'map'.
* tests/containers.scm ("eval/container, non-empty load path"): New test.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-07-19 11:53:47 +0200'>2019-07-19</span></td><td><a href='/guix/commit/tests/containers.scm?id=bacfec8611530dc3e849fb804b51f50b299796f0'>linux-container: Add 'eval/container'.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/system/linux-container.scm (eval/container): New procedure.
* tests/containers.scm ("eval/container, exit status")
("eval/container, writable user mapping"): New tests.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-04-02 18:15:37 +0200'>2019-04-02</span></td><td><a href='/guix/commit/tests/containers.scm?id=af76c020bf19de5fe2e92f31d8b85cbd55c481de'>linux-container: Make the guest UID and GID a parameter.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/build/linux-container.scm (initialize-user-namespace): Add
 #:guest-uid and #:guest-gid parameters and honor them.
(run-container): Likewise.
(call-with-container): Likewise.
* tests/containers.scm ("call-with-container, user namespace, guest UID/GID"):
New test.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2017-05-31 17:08:45 +0200'>2017-05-31</span></td><td><a href='/guix/commit/tests/containers.scm?id=3e894917414239cab1737d89feb263e0825ae7c5'>tests: Fix race condition in 'container-excursion*' test.</a><span class='msg-avail'>...<span class='msg-tooltip'>* tests/containers.scm ("container-excursion*"): Move (namespace pid)
call before (kill pid SIGKILL).
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2017-02-07 00:08:10 +0100'>2017-02-07</span></td><td><a href='/guix/commit/tests/containers.scm?id=c90db25f4cf1f98f3f4f3af38d175a14ffb8c32a'>linux-container: Add 'container-excursion*'.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/build/linux-container.scm (container-excursion*): New procedure.
* tests/containers.scm ("container-excursion*")
("container-excursion*, same namespaces"): New tests.
</span></span></td><td>Ludovic Courtès</td></tr>