Fix undefined function error message

This got fixed on 7.3, but the implementation is slightly different
on master and the new test was failing.

Author: nikic

Zend/zend_vm_def.h

@@ -784,16 +784,10 @@ ZEND_VM_COLD_HELPER(zend_undefined_function_helper, ANY, ANY)
 {
 	USE_OPLINE
 	zval *function_name;
-	char *name;
 
 	SAVE_OPLINE();
 	function_name = RT_CONSTANT(opline, opline->op2);
-	if (opline->opcode == ZEND_INIT_NS_FCALL_BY_NAME) {
-		name = Z_STRVAL_P(function_name + 2);
-	} else {
-		name = Z_STRVAL_P(function_name);
-	}
-	zend_throw_error(NULL, "Call to undefined function %s()", name);
+	zend_throw_error(NULL, "Call to undefined function %s()", Z_STRVAL_P(function_name));
 	HANDLE_EXCEPTION();
 }
 

Zend/zend_vm_execute.h

@@ -474,16 +474,10 @@ static zend_never_inline ZEND_COLD ZEND_OPCODE_HANDLER_RET ZEND_FASTCALL zend_un
 {
 	USE_OPLINE
 	zval *function_name;
-	char *name;
 
 	SAVE_OPLINE();
 	function_name = RT_CONSTANT(opline, opline->op2);
-	if (opline->opcode == ZEND_INIT_NS_FCALL_BY_NAME) {
-		name = Z_STRVAL_P(function_name + 2);
-	} else {
-		name = Z_STRVAL_P(function_name);
-	}
-	zend_throw_error(NULL, "Call to undefined function %s()", name);
+	zend_throw_error(NULL, "Call to undefined function %s()", Z_STRVAL_P(function_name));
 	HANDLE_EXCEPTION();
 }