Fix Isset and Empty with FiberScope

Author: ondrejmirtes

src/Analyser/NodeScopeResolver.php

@@ -3843,9 +3843,10 @@ function (MutatingScope $scope) use ($stmt, $expr, $nodeCallback, $context, $sto
 				$this->callNodeCallback($nodeCallback, $expr->name, $scope, $storage);
 			}
 		} elseif ($expr instanceof Expr\Empty_) {
+			$this->processExprNode($stmt, $expr->expr, $scope, $storage, new NoopNodeCallback(), $context->enterDeep());
 			$nonNullabilityResult = $this->ensureNonNullability($scope, $expr->expr);
 			$scope = $this->lookForSetAllowedUndefinedExpressions($nonNullabilityResult->getScope(), $expr->expr);
-			$result = $this->processExprNode($stmt, $expr->expr, $scope, $storage, $nodeCallback, $context->enterDeep());
+			$result = $this->processExprNode($stmt, $this->deepNodeCloner->cloneNode($expr->expr), $scope, $storage, $nodeCallback, $context->enterDeep());
 			$scope = $result->getScope();
 			$hasYield = $result->hasYield();
 			$throwPoints = $result->getThrowPoints();
@@ -3860,9 +3861,10 @@ function (MutatingScope $scope) use ($stmt, $expr, $nodeCallback, $context, $sto
 			$nonNullabilityResults = [];
 			$isAlwaysTerminating = false;
 			foreach ($expr->vars as $var) {
+				$this->processExprNode($stmt, $var, $scope, $storage, new NoopNodeCallback(), $context->enterDeep());
 				$nonNullabilityResult = $this->ensureNonNullability($scope, $var);
 				$scope = $this->lookForSetAllowedUndefinedExpressions($nonNullabilityResult->getScope(), $var);
-				$result = $this->processExprNode($stmt, $var, $scope, $storage, $nodeCallback, $context->enterDeep());
+				$result = $this->processExprNode($stmt, $this->deepNodeCloner->cloneNode($var), $scope, $storage, $nodeCallback, $context->enterDeep());
 				$scope = $result->getScope();
 				$hasYield = $hasYield || $result->hasYield();
 				$throwPoints = array_merge($throwPoints, $result->getThrowPoints());