This is used for exporting symbols when Cogl-Path becomes a DLL (.so)
of its own, so one can use and process this file with a preprocessor for
e.g. and generate a .def file that can be used for this purpose. Dist the
symbols file as well.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit 5037d81a1c68cfa9a052b9b081187e717b59b54b)
