Fixes 'multiple definition errors' when building with GCC 10+

From: https://bugs.gentoo.org/710796
Originally from: https://gitlab.freedesktop.org/pipewire/pipewire/-/commit/a62e41e
and https://gitlab.freedesktop.org/pipewire/pipewire/-/commit/7a976c7

--- a/spa/plugins/bluez5/a2dp-codecs.h
+++ b/spa/plugins/bluez5/a2dp-codecs.h
@@ -284,15 +284,15 @@
         }
 }
 
-const a2dp_sbc_t bluez_a2dp_sbc;
+extern const a2dp_sbc_t bluez_a2dp_sbc;
 #if ENABLE_MP3
-const a2dp_mpeg_t bluez_a2dp_mpeg;
+extern const a2dp_mpeg_t bluez_a2dp_mpeg;
 #endif
 #if ENABLE_AAC
-const a2dp_aac_t bluez_a2dp_aac;
+extern const a2dp_aac_t bluez_a2dp_aac;
 #endif
 #if ENABLE_APTX
-const a2dp_aptx_t bluez_a2dp_aptx;
+extern const a2dp_aptx_t bluez_a2dp_aptx;
 #endif
 
 #endif
--- a/spa/plugins/bluez5/bluez5-monitor.c
+++ b/spa/plugins/bluez5/bluez5-monitor.c
@@ -75,7 +75,7 @@
 	struct spa_list transport_list;
 };
 
-struct spa_handle_factory spa_a2dp_sink_factory;
+extern struct spa_handle_factory spa_a2dp_sink_factory;
 
 static void fill_item(struct spa_bt_monitor *this, struct spa_bt_transport *transport,
 		struct spa_pod **result, struct spa_pod_builder *builder)
--- a/spa/plugins/bluez5/meson.build
+++ b/spa/plugins/bluez5/meson.build
@@ -1,7 +1,8 @@
 
 bluez5_sources = ['plugin.c',
 		  'a2dp-sink.c',
-                  'bluez5-monitor.c']
+		  'a2dp-codecs.c',
+		  'bluez5-monitor.c']
 
 bluez5lib = shared_library('spa-bluez5',
 	bluez5_sources,
l.in?id=2d4b61d014ce6daba6bc6c39df77a0c46cffe55c'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/etc/guix-daemon.cil.in'>
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<div class='path'>path: <a href='/guix/log/?id=2d4b61d014ce6daba6bc6c39df77a0c46cffe55c'>root</a>/<a href='/guix/log/etc?id=2d4b61d014ce6daba6bc6c39df77a0c46cffe55c'>etc</a>/<a href='/guix/log/etc/guix-daemon.cil.in?id=2d4b61d014ce6daba6bc6c39df77a0c46cffe55c'>guix-daemon.cil.in</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/etc/guix-daemon.cil.in?id=2d4b61d014ce6daba6bc6c39df77a0c46cffe55c&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2022-12-23 20:20:06 +0100'>2022-12-23</span></td><td><a href='/guix/commit/etc/guix-daemon.cil.in?id=afaeb657b118e6998342110deab8c8110b824417'>etc: SELinux: Allow init process to setattr on profile directories.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/guix-daemon.cil.in: Add rule.
</span></span></td><td>Ricardo Wurmus</td></tr>
<tr><td><span title='2022-12-23 20:20:06 +0100'>2022-12-23</span></td><td><a href='/guix/commit/etc/guix-daemon.cil.in?id=4a134ed32e69ba888d988d2ed924a1531a54551b'>etc: SELinux: Allow daemon to search run state directories.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/guix-daemon.cil.in: Import types init_var_run_t and
system_dbusd_var_run_t; add rules.
</span></span></td><td>Ricardo Wurmus</td></tr>
<tr><td><span title='2022-12-23 20:20:06 +0100'>2022-12-23</span></td><td><a href='/guix/commit/etc/guix-daemon.cil.in?id=f28d792719abb82cc920486e6d6f14eacc44370c'>etc: SELinux: Label guix-daemon executable in profile.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/guix-daemon.cil.in: Add file rule for "guix-daemon" in current-guix
profile.
</span></span></td><td>Ricardo Wurmus</td></tr>
<tr><td><span title='2022-01-26 09:31:45 +0100'>2022-01-26</span></td><td><a href='/guix/commit/etc/guix-daemon.cil.in?id=bbc2fb0d52128c85c92251ed36d8063b3dcf3c3a'>etc: Remove redundant SELinux permissions block.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/guix-daemon.cil.in (guix_daemon): Consolidate two blocks adding
sock_file permissions on guix_daemon_conf_t.
</span></span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2022-01-24 11:28:14 +0100'>2022-01-24</span></td><td><a href='/guix/commit/etc/guix-daemon.cil.in?id=98e74d520a30d1ed7d7b47d4f1d9afadefc699e3'>etc: Add more SELinux permissions for the daemon.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/guix-daemon.cil.in (guix_daemon): Permit write on guix_daemon_conf_t
sock_file, necessary for garbage collection.
</span></span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2021-05-22 19:53:17 +0200'>2021-05-22</span></td><td><a href='/guix/commit/etc/guix-daemon.cil.in?id=35bd94a49257bbadcb3ca25342e5c1ec33f438f0'>etc: Add more SELinux permissions for the daemon.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/guix-daemon.cil.in (guix_daemon): Add more permissions, necessary for
garbage collection.
</span></span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2020-12-10 23:48:42 +0100'>2020-12-10</span></td><td><a href='/guix/commit/etc/guix-daemon.cil.in?id=d677f3d6231d352fdb65b70f67d85fb5744e912c'>etc: Add more SELinux permissions for the daemon.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/guix-daemon.cil.in (guix_daemon): Permit file write, getattr, link and
unlink for the guix_daemon_exec_t type.
</span></span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2020-11-27 21:33:59 +0100'>2020-11-27</span></td><td><a href='/guix/commit/etc/guix-daemon.cil.in?id=1807632393d0723f3085c457517965c32715717a'>etc: Add more SELinux permissions for the daemon.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/guix-daemon.cil.in (guix_daemon): Permit more operations required for
various build jobs.
</span></span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2020-11-26 00:31:47 +0100'>2020-11-26</span></td><td><a href='/guix/commit/etc/guix-daemon.cil.in?id=402ebffe195890c9826cfa7519034dd12a48ae6a'>etc: Add more SELinux permissions for the daemon.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/guix-daemon.cil.in (guix_daemon): Permit file appending, setattr,
read/write UDP sockets, access to tmpfs and hugetlbfs, and connecting to
PostgreSQL.
</span></span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2020-11-25 23:24:52 +0100'>2020-11-25</span></td><td><a href='/guix/commit/etc/guix-daemon.cil.in?id=d64e0261d0007413a795c4cf01f9d06b170da3f5'>etc: Add more SELinux permissions for the daemon.</a><span class='msg-avail'>...<span class='msg-tooltip'>This is needed for some package test suites.

* etc/guix-daemon.cil.in (guix_daemon): Permit unix_dgram_socket operations.
</span></span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2020-11-15 16:08:47 +0100'>2020-11-15</span></td><td><a href='/guix/commit/etc/guix-daemon.cil.in?id=62343288ef6dc56027d268ef773ae699a4bbb76d'>etc: Updates for the guix-daemon SELinux policy.</a><span class='msg-avail'>...<span class='msg-tooltip'>* etc/guix-daemon.cil.in (guix_daemon): Specify more permissions for
guix-daemon to account for daemon updates and newer SELinux.

I can't promise that this is a complete list of everything that guix-daemon
needs, but it's probably most of them. It can search for, install, upgrade,
and remove packages, create virtual machines and containers, update itself,
and so on.

Signed-off-by: Marius Bakke &lt;marius@gnu.org&gt;
</span></span></td><td>Daniel Brooks</td></tr>