meson: gio/tests: add more gio tests

Need to fix up some of the tests a little, because the
test binary will not necessarily be run from the current
build sub-directory, and the build directory structure
might not always be a mirror of the source directory
structure, so pass location of glib-mkenums and
glib-compile-scheme and such directly.

gio/tests/appinfo.c

@@ -2,6 +2,7 @@
 #include <locale.h>
 #include <string.h>
 
+#include <glib/gstdio.h>
 #include <gio/gio.h>
 #include <gio/gdesktopappinfo.h>
 
@@ -474,10 +475,18 @@ test_from_keyfile (void)
 int
 main (int argc, char *argv[])
 {
+  const gchar *build_dir;
+
   g_setenv ("XDG_CURRENT_DESKTOP", "GNOME", TRUE);
 
   g_test_init (&argc, &argv, NULL);
 
+  /* With Meson build we need to change into right directory, so that the
+   * appinfo-test binary can be found. */
+  build_dir = g_getenv ("G_TEST_BUILDDIR");
+  if (build_dir)
+    g_chdir (build_dir);
+
   g_test_add_func ("/appinfo/basic", test_basic);
   g_test_add_func ("/appinfo/text", test_text);
   g_test_add_func ("/appinfo/launch", test_launch);