Implement UnaryPlusHandler

[staabm]

as in

• phpstan-src/src/Analyser/MutatingScope.php

  Lines 1129 to 1131 in 6cf0ab2

  	if ($node instanceof Node\Expr\UnaryPlus) {
  	return $this->getType($node->expr)->toNumber();
  	}

• phpstan-src/src/Analyser/NodeScopeResolver.php

  Lines 3626 to 3640 in 6cf0ab2

  	} elseif (
  	$expr instanceof Expr\BitwiseNot
  	|| $expr instanceof Cast
  	|| $expr instanceof Expr\Clone_
  	|| $expr instanceof Expr\UnaryMinus
  	|| $expr instanceof Expr\UnaryPlus
  	) {
  	$result = $this->processExprNode($stmt, $expr->expr, $scope, $nodeCallback, $context->enterDeep());
  	$throwPoints = $result->getThrowPoints();
  	$impurePoints = $result->getImpurePoints();
  	$isAlwaysTerminating = $result->isAlwaysTerminating();
  	$hasYield = $result->hasYield();
  	$scope = $result->getScope();
  	} elseif ($expr instanceof Expr\Eval_) {

[phpstan-bot]

This pull request has been marked as ready for review.

[ondrejmirtes]

Thank you!