Allow aliasing namespaces containing reserved class names

This reverts commit b9f7123c5e.

Fixes GH-11152
Closes GH-11153

NEWS

@@ -2,6 +2,10 @@ PHP                                                                        NEWS
 |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 ?? ??? ????, PHP 8.2.7
 
+- Core:
+  . Fixed bug GH-11152 (Unable to alias namespaces containing reserved class
+    names). (ilutov)
+
 - Opcache:
   . Fixed bug GH-11134 (Incorrect match default branch optimization). (ilutov)
 

Zend/tests/gh11152.phpt

@@ -0,0 +1,20 @@
+--TEST--
+GH-11152: Allow aliasing namespaces containing reserved class names
+--FILE--
+<?php
+
+namespace string;
+
+use string as StringAlias;
+
+class C {}
+
+function test(StringAlias\C $o) {
+    var_dump($o::class);
+}
+
+test(new C());
+
+?>
+--EXPECT--
+string(8) "string\C"

Zend/tests/use_statement/aliasing_builtin_types.phpt

@@ -1,10 +0,0 @@
---TEST--
-Aliasing built-in types
---FILE--
-<?php
-
-use bool as A;
-
-?>
---EXPECTF--
-Fatal error: Cannot alias 'bool' as it is a built-in type in %s on line %d

Zend/zend_compile.c

@@ -8124,12 +8124,6 @@ static void zend_compile_use(zend_ast *ast) /* {{{ */
 		zend_string *old_name = zend_ast_get_str(old_name_ast);
 		zend_string *new_name, *lookup_name;
 
-		/* Check that we are not attempting to alias a built-in type */
-		if (type == ZEND_SYMBOL_CLASS && zend_is_reserved_class_name(old_name)) {
-			zend_error_noreturn(E_COMPILE_ERROR,
-				"Cannot alias '%s' as it is a built-in type", ZSTR_VAL(old_name));
-		}
-
 		if (new_name_ast) {
 			new_name = zend_string_copy(zend_ast_get_str(new_name_ast));
 		} else {