Do not require return type for renamed trait constructor

Author: ondrejmirtes

src/Rules/Methods/MissingMethodReturnTypehintRule.php

@@ -32,6 +32,13 @@ public function getNodeType(): string
 public function processNode(Node $node, Scope $scope): array
 {
 $methodReflection = $node->getMethodReflection();
+if ($scope->isInTrait()) {
+$methodNode = $node->getOriginalNode();
+$originalMethodName = $methodNode->getAttribute('originalTraitMethodName');
+if ($originalMethodName === '__construct') {
+return [];
+}
+}
 $returnType = ParametersAcceptorSelector::selectSingle($methodReflection->getVariants())->getReturnType();
 
 if ($returnType instanceof MixedType && !$returnType->isExplicitMixed()) {

tests/PHPStan/Rules/Methods/MissingMethodReturnTypehintRuleTest.php

@@ -88,4 +88,9 @@ public function testBug4758(): void
 $this->analyse([__DIR__ . '/data/bug-4758.php'], []);
 }
 
+public function testBug9571(): void
+{
+$this->analyse([__DIR__ . '/data/bug-9571.php'], []);
+}
+
 }

tests/PHPStan/Rules/Methods/data/bug-9571.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace Bug9571;
+
+trait Foo {
+public function __construct() {}
+}
+
+class HelloWorld
+{
+use Foo {
+__construct as baseConstructor;
+}
+
+public function __construct()
+{
+$this->baseConstructor();
+}
+}