Doc: small fixes

This commit adds the GTestSubprocessFlags enum to the docs, and fixes
several minor typos in various places.

https://bugzilla.gnome.org/show_bug.cgi?id=703254

docs/reference/glib/glib-sections.txt

@@ -2940,6 +2940,7 @@ g_test_expect_message
 g_test_assert_expected_messages
 
 GTestTrapFlags
+GTestSubprocessFlags
 g_test_trap_subprocess
 g_test_trap_has_passed
 g_test_trap_reached_timeout

gio/gasyncresult.c

@@ -62,7 +62,7 @@
  * |[
  * void _theoretical_frobnitz_async (Theoretical         *t,
  *                                   GCancellable        *c,
- *                                   GAsyncReadyCallback *cb,
+ *                                   GAsyncReadyCallback  cb,
  *                                   gpointer             u);
  *
  * gboolean _theoretical_frobnitz_finish (Theoretical   *t,

gio/gtask.c

@@ -46,7 +46,7 @@
  *     Eventually, you will call a method such as
  *     g_task_return_pointer() or g_task_return_error(), which will
  *     save the value you give it and then invoke the task's callback
- *     function (waiting until the next next iteration of the main
+ *     function (waiting until the next iteration of the main
  *     loop first, if necessary). The caller will pass the #GTask back
  *     to the operation's finish function (as a #GAsyncResult), and
  *     you can use g_task_propagate_pointer() or the like to extract

glib/gtestutils.c

@@ -2483,13 +2483,13 @@ g_test_trap_fork (guint64        usec_timeout,
 
 /**
  * g_test_trap_subprocess:
- * @test_name:    Test to run in a subprocess
+ * @test_path:    Test to run in a subprocess
  * @usec_timeout: Timeout for the subprocess test in micro seconds.
  * @test_flags:   Flags to modify subprocess behaviour.
  *
- * Respawns the test program to run only @test_name in a subprocess.
+ * Respawns the test program to run only @test_path in a subprocess.
  * This can be used for a test case that might not return, or that
- * might abort. @test_name will normally be the name of the parent
+ * might abort. @test_path will normally be the name of the parent
  * test, followed by "<literal>/subprocess/</literal>" and then a name
  * for the specific subtest (or just ending with
  * "<literal>/subprocess</literal>" if the test only has one child