Normalize representation of parenthesized concat in php 7.4

Fixes nikic#123

Author: TysonAndre

ast.c

@@ -752,6 +752,13 @@ static void ast_to_zval(zval *zv, zend_ast *ast, ast_state_info_t *state) {
 				return;
 			}
 			break;
+#ifdef ZEND_PARENTHESIZED_CONCAT
+		case ZEND_AST_BINARY_OP:
+			if (ast->attr == ZEND_PARENTHESIZED_CONCAT) {
+				ast->attr = ZEND_CONCAT;
+			}
+			break;
+#endif
 #else
 		case ZEND_AST_CLASS_CONST:
 			if (state->version >= 70) {

tests/concat.phpt

@@ -0,0 +1,34 @@
+--TEST--
+AST_CONCAT with/without parenthesis
+--FILE--
+<?php
+// PHP 7.4 changed the internal representation of concatenation operations.
+// This tests that php-ast consistently exposes the AST in PHP 7.0-7.4
+// For https://github.com/nikic/php-ast/issues/123
+require __DIR__ . '/../util.php';
+
+$code = <<<'PHP'
+<?php
+require_once __DIR__ . '/first.php';
+require_once(__DIR__ . '/second.php');
+PHP;
+
+echo ast_dump(ast\parse_code($code, $version=70)), "\n";
+
+?>
+--EXPECTF--
+AST_STMT_LIST
+    0: AST_INCLUDE_OR_EVAL
+        flags: EXEC_REQUIRE_ONCE (%d)
+        expr: AST_BINARY_OP
+            flags: BINARY_CONCAT (%d)
+            left: AST_MAGIC_CONST
+                flags: MAGIC_DIR (%d)
+            right: "/first.php"
+    1: AST_INCLUDE_OR_EVAL
+        flags: EXEC_REQUIRE_ONCE (%d)
+        expr: AST_BINARY_OP
+            flags: BINARY_CONCAT (%d)
+            left: AST_MAGIC_CONST
+                flags: MAGIC_DIR (%d)
+            right: "/second.php"