fix(parser): correct __FUNCTION__ constant resolution in namespaced methods

- Fixed __FUNCTION__ to use short name instead of full namespaced name in method context
- Added conditional logic to prepend namespace only when not in method definition
- Added test case to verify proper behavior of __FUNCTION__ and __METHOD__ constants
- Ensured magic constants return correct values based on their usage context
- Updated parser logic to distinguish between function and method definitions properly

src/Parser/ConstantExpressionTrait.php

@@ -139,7 +139,10 @@ trait ConstantExpressionTrait
     {
         $class = $this->classDef?->getNamespacedName(false)
             ?? (($this->namespace ? $this->namespace . '\\' : '') . $this->class);
-        $function = ($this->namespace ? $this->namespace . '\\' : '') . $this->function;
+        $function = $this->function;
+        if ($function !== '' && $this->methodDef === null && $this->namespace !== '') {
+            $function = $this->namespace . '\\' . $function;
+        }
         switch ($expr->getType()) {
             case 'Scalar_MagicConst_Dir':
                 return '"' . $this->escapeString($this->dir) . '"';

tests/compiler/namespace/magic-function-method.phpt

@@ -0,0 +1,34 @@
+--TEST--
+__FUNCTION__ uses the short name in namespaced methods
+--FILE--
+<?php
+namespace MagicFunctionMethod {
+    class Example {
+        public function instanceMethod(): void {
+            echo __FUNCTION__, "\n", __METHOD__, "\n";
+        }
+
+        public static function staticMethod(): void {
+            echo __FUNCTION__, "\n", __METHOD__, "\n";
+        }
+    }
+
+    function namespacedFunction(): void {
+        echo __FUNCTION__, "\n";
+    }
+}
+
+namespace {
+    function main(): void {
+        (new \MagicFunctionMethod\Example())->instanceMethod();
+        \MagicFunctionMethod\Example::staticMethod();
+        \MagicFunctionMethod\namespacedFunction();
+    }
+}
+?>
+--EXPECT--
+instanceMethod
+MagicFunctionMethod\Example::instanceMethod
+staticMethod
+MagicFunctionMethod\Example::staticMethod
+MagicFunctionMethod\namespacedFunction