exception expected when passing non-object to `object` typed parameter

[jakubmisek]

when passing values to arguments typed as object, the behavior is unexpected.

<?php

function f(object $o) {  }
$a = 123;
f($a);

$f = "f";
$f($a);

Actual:

• Both compile-time calls and dynamic calls use an invalid conversion ~ PhpValue.AsObject().
• Value 123 is "converted" to null
• function f() checks $o if it's not null and throws argnull exception
• function f() may not check argument for null, if the argument $o is nullable
• in case f() is a CLR/C# method, it gets null silently without any warning or runtime check

Expected:

• TypeError exception should be thrown.
• StrictConvert.ToObject should be used to either get object or null or TypeError exception