flatpak: add helpers to locate flatpak installation debug dirs

The goal here is to be able to locate all of the debug directories for
active flatpak runtimes so that we can possibly decode debug libraries
from them (after verifying build-id/CRC).

src/tests/meson.build

@@ -50,6 +50,13 @@ test_mountinfo = executable('test-mountinfo',
   dependencies: test_deps,
 )
 
+test_flatpak = executable('test-flatpak',
+  [ 'test-flatpak.c',
+    '../libsysprof/sysprof-flatpak.c'],
+        c_args: test_cflags,
+  dependencies: test_deps,
+)
+
 
 if get_option('enable_gtk')
 

src/tests/test-flatpak.c

@@ -0,0 +1,13 @@
+#include "sysprof-flatpak.h"
+
+gint
+main (gint   argc,
+      gchar *argv[])
+{
+  g_auto(GStrv) debug_dirs = sysprof_flatpak_debug_dirs ();
+
+  for (guint i = 0; debug_dirs[i]; i++)
+    g_print ("%s\n", debug_dirs[i]);
+
+  return 0;
+}