Function g_signal_newv
pub unsafe extern "C" fn g_signal_newv(
signal_name: *const i8,
itype: usize,
signal_flags: u32,
class_closure: *mut GClosure,
accumulator: Option<unsafe extern "C" fn(*mut GSignalInvocationHint, *mut GValue, *const GValue, *mut c_void) -> i32>,
accu_data: *mut c_void,
c_marshaller: Option<unsafe extern "C" fn(*mut GClosure, *mut GValue, u32, *const GValue, *mut c_void, *mut c_void)>,
return_type: usize,
n_params: u32,
param_types: *mut usize,
) -> u32