Remove self/parent/static restriction for namespace names

This no longer applies as of PHP 8.0.

Author: nikic

lib/PhpParser/ParserAbstract.php

@@ -898,13 +898,6 @@ protected function checkTryCatch(TryCatch $node) {
     }
 
     protected function checkNamespace(Namespace_ $node) {
-        if ($node->name && $node->name->isSpecialClassName()) {
-            $this->emitError(new Error(
-                sprintf('Cannot use \'%s\' as namespace name', $node->name),
-                $node->name->getAttributes()
-            ));
-        }
-
         if (null !== $node->stmts) {
             foreach ($node->stmts as $stmt) {
                 if ($stmt instanceof Namespace_) {

test/code/parser/expr/keywordsInNamespacedName.test

@@ -3,6 +3,9 @@ Keywords in namespaced name
 <?php
 namespace fn;
 namespace fn\use;
+namespace self;
+namespace parent;
+namespace static;
 fn\use();
 \fn\use();
 namespace\fn\use();
@@ -25,6 +28,33 @@ array(
                 1: use
             )
         )
+        stmts: array(
+        )
+    )
+    2: Stmt_Namespace(
+        name: Name(
+            parts: array(
+                0: self
+            )
+        )
+        stmts: array(
+        )
+    )
+    3: Stmt_Namespace(
+        name: Name(
+            parts: array(
+                0: parent
+            )
+        )
+        stmts: array(
+        )
+    )
+    4: Stmt_Namespace(
+        name: Name(
+            parts: array(
+                0: static
+            )
+        )
         stmts: array(
             0: Stmt_Expression(
                 expr: Expr_FuncCall(

test/code/parser/stmt/namespace/invalidName.test

@@ -1,51 +1,5 @@
 Invalid namespace names
 -----
-<?php namespace self;
------
-Cannot use 'self' as namespace name from 1:17 to 1:20
-array(
-    0: Stmt_Namespace(
-        name: Name(
-            parts: array(
-                0: self
-            )
-        )
-        stmts: array(
-        )
-    )
-)
------
-<?php namespace PARENT;
------
-Cannot use 'PARENT' as namespace name from 1:17 to 1:22
-array(
-    0: Stmt_Namespace(
-        name: Name(
-            parts: array(
-                0: PARENT
-            )
-        )
-        stmts: array(
-        )
-    )
-)
------
-<?php namespace static;
------
-!!php7
-Cannot use 'static' as namespace name from 1:17 to 1:22
-array(
-    0: Stmt_Namespace(
-        name: Name(
-            parts: array(
-                0: static
-            )
-        )
-        stmts: array(
-        )
-    )
-)
------
 <?php use A as self;
 -----
 Cannot use A as self because 'self' is a special class name from 1:16 to 1:19