[DeadCode] Add RemovePsr4AutoloadedIncludeRector

[TomasVotruba]

Inspired at https://www.reddit.com/r/PHP/comments/1unb59g/i_built_a_static_analysis_tool_that_finds_require/

I'm surprised we don't have this rule yet, so obvious :)

Caveats

• verify dir autoload?

---

Adds RemovePsr4AutoloadedIncludeRector (DeadCode). Removes a standalone include/require when the target file is already covered by a PSR-4 autoload mapping in composer.json — the composer autoloader loads the class anyway, so the manual require is dead.

Before / after

-require __DIR__ . '/src/SomeClass.php';
-
 $someClass = new App\SomeClass();

with composer.json:

{
    "autoload": {
        "psr-4": { "App\\": "src" }
    }
}

How it decides

1. Matches only a bare statement require X; (skips $x = require ...;).
2. Resolves the target path (__DIR__ . '/rel.php', absolute, or relative literal) against the current file dir.
3. Parses the target; bails unless it declares exactly one class — otherwise removing the require would drop the other definitions.
4. Reads autoload + autoload-dev PSR-4 from composer.json (auto-found at project root via getcwd(), or set COMPOSER_JSON_PATH).
5. Removes only if the declared FQCN maps back to that exact file through a PSR-4 prefix.

Skips (covered by fixtures)

• file not under any PSR-4 path
• file declaring 2+ classes
• $x = require ...; (non-standalone include)

Configurable rule (does filesystem I/O), so it is not added to the dead-code level set — opt-in via config.

[samsonasik]

I think this should skip if the class has side effect directly in target source:

namespace App;

class Cli 
{
    public static function init() {
         // init cli ...
    }
}

// here init on purpose
Cli::init();

for example

https://github.com/codeigniter4/CodeIgniter4/blob/d9ec94b7ec4bbded8d66a8dc07ed8ceb7f402f69/system/CLI/CLI.php#L1191-L1192

[lll-lll-lll-lll]

@TomasVotruba Would it be OK if I opened a small PR against this branch to address the side-effect skip @samsonasik mentioned?

The idea would be to bail out unless the target file's top level contains only type declarations (class-like declarations, use statements, statement-form declare, and comments). Top-level functions and constants would also cause it to bail, since autoloading doesn't eagerly define them. I'd include fixtures as well.

[TomasVotruba]

@lll-lll-lll-lll Sure, go for it 👌

[TomasVotruba]

I didn't merge this yet because I was not sure about its application.
On second hand, there might be couple cases we haven't thought of. Untill we actually have to upgrade a project with such cases, I'm closing it to keep it safe.

Idea is here if needed 👍