ext/standard: add test triggering deprecation when reading $http_response_header via a dynamic fetch

And thus remove the TODO message in zend_compile.c.

Author: LamentXU123

Zend/zend_compile.c

@@ -2971,7 +2971,6 @@ static zend_op *zend_compile_simple_var_no_cv(znode *result, const zend_ast *ast
 
 		opline->extended_value = ZEND_FETCH_GLOBAL;
 	} else {
-		// TODO: Have a test case for this?
 		if (name_node.op_type == IS_CONST
 			&& type == BP_VAR_R
 			&& zend_string_equals_literal(Z_STR(name_node.u.constant), "http_response_header")) {

ext/standard/tests/http/http_response_header_deprecated_dynamic_fetch.phpt

@@ -0,0 +1,16 @@
+--TEST--
+$http_response_header dynamic fetch should warn
+--FILE--
+<?php
+
+function http_response_header() {
+    ${__FUNCTION__} = "OK";
+    var_dump(${__FUNCTION__});
+}
+
+http_response_header();
+
+?>
+--EXPECTF--
+Deprecated: The predefined locally scoped $http_response_header variable is deprecated, call http_get_last_response_headers() instead in %s on line %d
+string(2) "OK"