Fix #909 - support private trait aliasing

src/Psalm/Internal/Visitor/ReflectorVisitor.php

@@ -425,6 +425,10 @@ class ReflectorVisitor extends PhpParser\NodeVisitorAbstract implements PhpParse
                             case 2:
                                 $visibility_map[$new_name] = ClassLikeAnalyzer::VISIBILITY_PROTECTED;
                                 break;
+
+                            case 4:
+                                $visibility_map[$new_name] = ClassLikeAnalyzer::VISIBILITY_PRIVATE;
+                                break;
                         }
                     }
                 }

tests/TraitTest.php

@@ -889,6 +889,31 @@ class TraitTest extends TestCase
                     }',
                 'error_message' => 'TooFewArguments',
             ],
+            'traitMethodMadePrivate' => [
+                '<?php
+                    trait T {
+                        public function foo() : void {
+                            echo "here";
+                        }
+                    }
+
+                    class C {
+                        use T {
+                            foo as private traitFoo;
+                        }
+
+                        public function bar() : void {
+                            $this->traitFoo();
+                        }
+                    }
+
+                    class D extends C {
+                        public function bar() : void {
+                            $this->traitFoo(); // should fail
+                        }
+                    }',
+                'error_message' => 'InaccessibleMethod'
+            ],
         ];
     }
 }