meson: Enable echo-cancel module, add libwebrtc_util lib, add speex and webrtc dependencies

Signed-off-by: Arnaud Rebillout <arnaud.rebillout@collabora.com>

src/modules/echo-cancel/meson.build

@@ -0,0 +1,18 @@
+# The webrtc code is split off into a helper library to avoid having automake
+# link module-echo-cancel with C++ (which it does if there are any C++ deps,
+# even conditional ones).
+
+# Defining this library as shared fails, as it actually requires a symbol
+# from module-echo-cancel.c. Setting it to static solves that.
+
+libwebrtc_util_sources = [
+  'webrtc.cc'
+]
+
+libwebrtc_util = static_library('libwebrtc_util',
+  libwebrtc_util_sources,
+  cpp_args : [pa_c_args, server_c_args],
+  include_directories : [configinc, topinc],
+  dependencies : [libpulse_dep, libpulsecommon_dep, libpulsecore_dep, webrtc_dep],
+  install : true
+)