assiging to pointer parameters does not emit stind instruction

[adrianoc]

This is related to #184

class FixedStatementTest
{
    unsafe void DoIt(int *pp)
    {
        *pp = 42;
    }    
}

produces

//*pp = 42;
il_DoIt_2.Emit(OpCodes.Ldc_I4, 42);
il_DoIt_2.Emit(OpCodes.Starg_S, p_pp_3);
il_DoIt_2.Emit(OpCodes.Ret);

instead of something like :

//*pp = 42;
il_DoIt_2.Emit(OpCodes.Ldarg_1);
il_DoIt_2.Emit(OpCodes.Ldc_I4, 42);
il_DoIt_2.Emit(OpCodes.Stind_I4);
il_DoIt_2.Emit(OpCodes.Ret);