Check for `#[Override]` annotation

[thekid]

Implements #149, see https://wiki.php.net/rfc/marking_overriden_methods. In comparison with #172, these checks are always performed during compilation (even for PHP 8.3+, as there is no measurable performance impact in doing so and we prevent uncatchable fatal errors).

In a nutshell

This first example works without any problem (as would simply omitting this annotation):

use Override;
use lang\Throwable;

class CannotConnect extends Throwable {

  #[Override]
  public function compoundMessage() { }
}

The following all raise compile errors:

use Override;
use lang\{Runnable, Throwable};

// No parent class
class CannotConnect {

  #[Override]
  public function compoundMessage() { }
}

// Parent class doesn't have such a method
class CannotConnect extends Throwable {

  #[Override]
  public function composeMessage() { }
}

// None of the implemented interfaces have such a method
class RunOnce implements Runnable {

  #[Override]
  public function doRun() { }
}

Performance impact

👉 Not measurable

Before:

$ xp test src/test/php/
# ...
Test cases:  945 succeeded, 3 skipped
Memory used: 11531.30 kB (11585.42 kB peak)
Time taken:  0.227 seconds (0.636 seconds overall)

After:

$ xp test src/test/php/
# ...
Test cases:  955 succeeded, 3 skipped
Memory used: 11649.20 kB (11703.33 kB peak)
Time taken:  0.233 seconds (0.632 seconds overall)

[thekid]

Released in https://github.com/xp-framework/compiler/releases/tag/v8.15.0