Please describe the problem:
GLib module VAPI is wrong as it doesn't allow to specify a NULL file_name in open() and doesn't declare symbol as an out parameter in symbol()

Steps to reproduce:
GLib.Module module = GLib.Module.open(null, ModuleFlags.BIND_LAZY);
void * sym;
if(!module.symbol(handler_real_name, out sym)) {
 ...
}

Actual results:
At compile time:

warning: Argument 1: Cannot pass null to
non-null parameter type

error: Argument 2: Cannot pass out argument to
non-output parameter

Expected results:
Clean compile

Does this happen every time?
Yes

Other information:
Patch for glib-2.0.vapi:

1299,1300c1299,1300
< 		public static Module open (string? file_name, ModuleFlags @flags);
< 		public bool symbol (string symbol_name, out void** symbol);
---
> 		public static Module open (string file_name, ModuleFlags @flags);
> 		public bool symbol (string symbol_name, void** symbol);