Fix doc snarfing with GCC 4.5+.
From <http://git.savannah.gnu.org/cgit/guile.git/commit/?h=branch_release-1-8&id=aac41d28358cea594bb30f6e547afb82bb6004a6>.

diff --git a/scripts/snarf-check-and-output-texi b/scripts/snarf-check-and-output-texi
index ea33e17..8cd42e8 100755
--- a/scripts/snarf-check-and-output-texi
+++ b/scripts/snarf-check-and-output-texi
@@ -267,6 +267,17 @@ exec ${GUILE-guile} -l $0 -c "(apply $main (cdr (command-line)))" "$@"
       (set! *file* file)
       (set! *line* line))
 
+     ;; newer gccs like to throw around more location markers into the
+     ;; preprocessed source; these (hash . hash) bits are what they translate to
+     ;; in snarfy terms.
+     (('location ('string . file) ('int . line) ('hash . 'hash))
+      (set! *file* file)
+      (set! *line* line))
+
+     (('location ('hash . 'hash) ('string . file) ('int . line) ('hash . 'hash))
+      (set! *file* file)
+      (set! *line* line))
+
      (('arglist rest ...)
       (set! *args* (do-arglist rest)))
 class='tabs'><tr><td>
<a href='/guix/about/'>about</a><a href='/guix/'>summary</a><a href='/guix/refs/?id=f36ed4ddc286bc1105aff63c697e6fbb7310d3df'>refs</a><a class='active' href='/guix/log/gnu/services/xorg.scm'>log</a><a href='/guix/tree/gnu/services/xorg.scm?id=f36ed4ddc286bc1105aff63c697e6fbb7310d3df'>tree</a><a href='/guix/commit/gnu/services/xorg.scm?id=f36ed4ddc286bc1105aff63c697e6fbb7310d3df'>commit</a><a href='/guix/diff/gnu/services/xorg.scm?id=f36ed4ddc286bc1105aff63c697e6fbb7310d3df'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/services/xorg.scm'>
<input type='hidden' name='id' value='f36ed4ddc286bc1105aff63c697e6fbb7310d3df'/><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=f36ed4ddc286bc1105aff63c697e6fbb7310d3df'>root</a>/<a href='/guix/log/gnu?id=f36ed4ddc286bc1105aff63c697e6fbb7310d3df'>gnu</a>/<a href='/guix/log/gnu/services?id=f36ed4ddc286bc1105aff63c697e6fbb7310d3df'>services</a>/<a href='/guix/log/gnu/services/xorg.scm?id=f36ed4ddc286bc1105aff63c697e6fbb7310d3df'>xorg.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/gnu/services/xorg.scm?id=f36ed4ddc286bc1105aff63c697e6fbb7310d3df&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2024-05-30 22:40:23 +0100'>2024-05-30</span></td><td><a href='/guix/commit/gnu/services/xorg.scm?id=e51a930c5c5a8609b8656bf997ec853cc04391e7'>services: xorg: Add startx-command-service-type.</a><span class='msg-avail'>...</span></td><td>Tomas Volf</td></tr>
<tr><td><span title='2024-05-30 18:23:34 +0100'>2024-05-30</span></td><td><a href='/guix/commit/gnu/services/xorg.scm?id=9948816819e0af23587d75701ba81d797ef7ea29'>services: xorg: Add xorg-start-command-xinit procedure.</a><span class='msg-avail'>...</span></td><td>Tomas Volf</td></tr>
<tr><td><span title='2024-04-28 23:41:50 +0200'>2024-04-28</span></td><td><a href='/guix/commit/gnu/services/xorg.scm?id=72432080ad52aec261ae8a74afc3a2ee7254914a'>services: gdm: Use ‘make-forkexec-constructor’.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2024-03-20 14:54:26 +0000'>2024-03-20</span></td><td><a href='/guix/commit/gnu/services/xorg.scm?id=8fa07612644339a2bf21be9ee924e6ff1e0ec81d'>Merge remote-tracking branch 'savannah/master' into gnome-team</a><span class='msg-avail'>...</span></td><td>Christopher Baines</td></tr>
<tr><td><span title='2024-03-19 18:52:16 +0800'>2024-03-19</span></td><td><a href='/guix/commit/gnu/services/xorg.scm?id=3ea55fada0593cd05c686cef2f6a59ba65933ef5'>services: sddm: Add extension for localed-service-type.</a><span class='msg-avail'>...</span></td><td>Zheng Junjie</td></tr>
<tr><td><span title='2024-02-24 06:36:24 +0100'>2024-02-24</span></td><td><a href='/guix/commit/gnu/services/xorg.scm?id=06d01c610e3bee61e38a177aecda5982d5b338ae'>services: gdm: Enable wayland by default.</a><span class='msg-avail'>...</span></td><td>Vivien Kraus</td></tr>
<tr><td><span title='2024-01-05 17:28:54 +0100'>2024-01-05</span></td><td><a href='/guix/commit/gnu/services/xorg.scm?id=65af293c3736b2147c0af764414f2efe720e521e'>services: xorg: ‘dbus-daemon-wrapper’ handles Home profile.</a><span class='msg-avail'>...</span></td><td>Feng Shu</td></tr>
<tr><td><span title='2023-06-04 10:33:55 +0200'>2023-06-04</span></td><td><a href='/guix/commit/gnu/services/xorg.scm?id=f4f5ee6ad6e2432f52e37c549211df8f1cdbb571'>services: screen-locker-service-type: Configurable PAM and setuid.</a><span class='msg-avail'>...</span></td><td>muradm</td></tr>
<tr><td><span title='2023-05-11 13:21:45 +0200'>2023-05-11</span></td><td><a href='/guix/commit/gnu/services/xorg.scm?id=2df5d4fd18a2fbcb8066a50e2da8ec64635f5162'>system: pam: Let PAM extensions add shepherd requirements.</a><span class='msg-avail'>...</span></td><td>Josselin Poiret</td></tr>
<tr><td><span title='2023-03-25 10:06:36 +0800'>2023-03-25</span></td><td><a href='/guix/commit/gnu/services/xorg.scm?id=a7f118d062db4408b23505750c44a1f996496c43'>services: xorg-wrapper: Support xorg server input rewriting.</a><span class='msg-avail'>...</span></td><td>r0man</td></tr>
<tr><td><span title='2023-03-10 14:49:58 +0100'>2023-03-10</span></td><td><a href='/guix/commit/gnu/services/xorg.scm?id=5627c73a9e410c7e28d67df517bd275d8c5f5d8d'>services: xorg: Deprecate 'screen-locker-service' procedure.</a><span class='msg-avail'>...</span></td><td>Bruno Victal</td></tr>
<tr><td><span title='2022-11-18 15:44:39 +0100'>2022-11-18</span></td><td><a href='/guix/commit/gnu/services/xorg.scm?id=8d9647d8a77a67013c48166561134d92b5224264'>services: Add Shepherd 'configuration' action to various services.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2022-10-11 11:29:03 +0000'>2022-10-11</span></td><td><a href='/guix/commit/gnu/services/xorg.scm?id=683558e2ed8fd40ce29453b8136a95bedf55991a'>services: slim-service-type: Do not extend profile with xterm.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-10-07 10:11:13 -0400'>2022-10-07</span></td><td><a href='/guix/commit/gnu/services/xorg.scm?id=aad4e4fc6bed1209479970f1bcd2f08ee2b53d12'>services: xorg: Add auto-suspend? field to &lt;gdm-configuration&gt;.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-10-07 10:11:12 -0400'>2022-10-07</span></td><td><a href='/guix/commit/gnu/services/xorg.scm?id=7b896a26b8a911231d606b4fe664b03b95b27b39'>services: Add dconf-service-type.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-10-07 10:11:11 -0400'>2022-10-07</span></td><td><a href='/guix/commit/gnu/services/xorg.scm?id=1936668f5b7837104de4a091c8f6adf907ff9273'>services: gdm: Add a configuration field to enable XDMCP.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2022-09-16 16:27:08 -0400'>2022-09-16</span></td><td><a href='/guix/commit/gnu/services/xorg.scm?id=d7e56aebec4535f3567c362b6084818873e54b0d'>services: desktop: Mount /var/lib/gdm on a tmpfs file system.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>