Fix promoted readonly properties

[trowski]

This fixes detection of readonly on promoted properties as well as the visibility of promoted readonly properties.

https://psalm.dev/r/0df6074053

https://psalm.dev/r/910eec3285

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/0df6074053

<?php

class Test {	
	public function __construct(public readonly int $foo) {

	}
}

$x = new Test(1234);
$x->foo = 123;

Psalm output (using commit c21aefa):

ERROR: ParseError - 4:46 - Syntax error, unexpected T_STRING, expecting T_VARIABLE on line 4

ERROR: TooManyArguments - 9:6 - Too many arguments for Test::__construct - expecting 0 but saw 1

ERROR: UndefinedPropertyAssignment - 10:1 - Instance property Test::$foo is not defined

ERROR: InvalidDocblock - 4:30 - Param1 of Test::__construct has invalid syntax

https://psalm.dev/r/910eec3285

<?php

class Test {	
	public function __construct(private readonly int $foo) {

	}
}

$x = new Test(1234);
echo $x->foo;

Psalm output (using commit c21aefa):

ERROR: ParseError - 4:47 - Syntax error, unexpected T_STRING, expecting T_VARIABLE on line 4

ERROR: TooManyArguments - 9:6 - Too many arguments for Test::__construct - expecting 0 but saw 1

ERROR: UndefinedPropertyFetch - 10:6 - Instance property Test::$foo is not defined

INFO: MixedArgument - 10:6 - Argument 1 of echo cannot be mixed, expecting string

ERROR: InvalidDocblock - 4:30 - Param1 of Test::__construct has invalid syntax

[orklah]

Thanks! That's great!