Emit redundant/impossible condition when the result of a pure getter is compared to itself

[weirdan]

https://psalm.dev/r/2b1b91e0d1

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/2b1b91e0d1

<?php
/** @psalm-immutable */
final class Mass {
    public function __construct(private int $value) {}
    public function getValue(): int { return $this->value; }
}

$masses = [new Mass(1), new Mass(2)];

foreach ($masses as $mass) {
    if ($mass->getValue() === $mass->getValue()) {} // should be flagged as RedundantCondition
    if ($mass->getValue() !== $mass->getValue()) {} // should be flagged as impossible
}

Psalm output (using commit a2c87b8):

No issues!