[perf] Drop AstResolver from named-arg position resolution

[TomasVotruba]

What

RemoveMethodCallParamRector and ArgumentDefaultValueReplacer both resolve a named-argument position by reading the parameter name at a given index of the called method/function. They did this via AstResolver->resolveClassMethodOrFunctionFromCall(), which re-parses the callee's source file into a decorated AST — heavy — only to read $param->var->name.

This swaps that for ReflectionResolver->resolveFunctionLikeReflectionFromCall() + ParametersAcceptorSelector, reading the name straight off ParameterReflection::getName(). No file re-parse.

$reflection = $this->reflectionResolver->resolveFunctionLikeReflectionFromCall($node);
if (! $reflection instanceof MethodReflection && ! $reflection instanceof FunctionReflection) {
    return null;
}
$parametersAcceptor = ParametersAcceptorSelector::combineAcceptors($reflection->getVariants());
$parameterReflection = $parametersAcceptor->getParameters()[$position] ?? null;

Same pattern already used by CallLikeParamDefaultResolver.

Why

AstResolver is one of the costlier analyses in the engine (parses extra files beyond the one being processed). These two sites needed only metadata reflection already holds, so the parse was pure overhead. The branch is only hit when a call uses named arguments, but removing the dependency is free correctness/perf.

Scope note

Only the two sites that need just the param name are converted. Other AstResolver callers genuinely need the AST (default-value expressions, attributes, method bodies, docblocks) and are left untouched.

Tests

Existing named-argument fixtures (remove_named_arguments, replace_named_arguments) cover the changed branch. vendor/bin/phpunit rules-tests/Arguments green (37 tests). ECS + PHPStan clean.