Previously the unit tests were using libdl without directly linking to
it. It looks like this ends up working because one of Cogl's
dependencies ends up pulling adding -ldl via libtool. However in some
configurations it looks like this wasn't happening.
To avoid this problem we can just use GModule to resolve the symbols.
g_module_open is documented to return a handle to the ‘main program’
when NULL is passed as the filename and looking at the code it seems
that this ends up using RTLD_DEFAULT so it will have the same effect.
The in-tree copy of glib already has the code for gmodule so this
shouldn't cause problems for --disable-glib.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
(cherry picked from commit b14ece116ed3e4b18d59b645e77b3449fac51137)
e6fb1fb433