Fix GH-12558 Escape \N and \n in generated stubs

Author: kocsismate

build/gen_stub.php

@@ -524,10 +524,10 @@ public function toOptimizerTypeMask(): string {
     }
 
     public function toEscapedName(): string {
-        // Escape backslashes, and also encode \u and \U to avoid compilation errors in generated macros
+        // Escape backslashes, and also encode \u, \U, \n, and \N to avoid compilation errors in generated macros
         return str_replace(
-            ['\\', '\\u', '\\U'],
-            ['\\\\', '\\\\165', '\\\\125'],
+            ['\\', '\\u', '\\U', '\\n', '\\N'],
+            ['\\\\', '\\\\165', '\\\\125', '\\\\156', '\\\\116'],
             $this->name
         );
     }

ext/zend_test/test.stub.php

@@ -254,6 +254,11 @@ class UnlikelyCompileError {
         public function method(): ?UnlikelyCompileError {}
     }
 
+    class NotUnlikelyCompileError {
+        /* This method signature would create a compile error due to the string
+         * "ZendTestNS\NotUnlikelyCompileError" in the generated macro call */
+        public function method(): ?UnlikelyCompileError {}
+    }
 }
 
 namespace ZendTestNS2 {

ext/zend_test/test_arginfo.h

@@ -11,6 +11,8 @@ $foo->foo = new \ZendTestNS2\ZendSubNS\Foo();
 var_dump($foo);
 $foo = new \ZendTestNS\UnlikelyCompileError();
 var_dump($foo);
+$foo = new \ZendTestNS\NotUnlikelyCompileError();
+var_dump($foo);
 ?>
 --EXPECTF--
 object(ZendTestNS2\Foo)#%d (%d) {
@@ -24,3 +26,5 @@ object(ZendTestNS2\Foo)#%d (%d) {
 }
 object(ZendTestNS\UnlikelyCompileError)#%d (%d) {
 }
+object(ZendTestNS\NotUnlikelyCompileError)#%d (%d) {
+}