Update changelog

Author: nikic

package.xml

@@ -26,11 +26,21 @@
 - Fix issue #51: Make nullable array/callable have a flag of 0 in inner element, in version 40.
 - Added a constructor for the ast\Node class.
 - Added ast\flags\FUNC_GENERATOR constant, which is used since PHP 7.1.
+- Added ast\flags\FUNC_RETURNS_REF constant, intended to supersede ast\flags\RETURNS_REF.
+- Added ast\flags\CLOSURE_USE_REF constant, used by AST_CLOSURE_VAR nodes. Previously "1" was used.
 - Added version 45 with the following changes (PHP 7.2 support):
-  - Object type hints are recognized.
+  - An `object` type annotation now returns an `AST_TYPE` with `TYPE_OBJECT` flag, rather than
+    treating `object` as a class name.
 - Added version 50 with the following changes:
-  - Add __declId to info about Decl nodes, to make it easier for php-ast callers
-    to process multiple similar Decl definitions (e.g. closures) on the same line.
+  - `ast\Node\Decl` nodes are no longer generated. AST kinds `AST_FUNCTION`, `AST_METHOD`,
+    `AST_CLOSURE` and `AST_CLASS` now also use the normal `ast\Node` class. The `name` and
+    `docComment` properties are now represented as children. The `endLineno` is still represented as
+    an (undeclared) property.
+  - An integer `__declId` has been added to declaration nodes of kind `AST_FUNCTION`, `AST_METHOD`,
+    `AST_CLOSURE` and `AST_CLASS`. The `__declId` uniquely identifies a declaration within the
+	parsed code and will remain the same if the code is parsed again. This is useful to distinguish
+	closures declared on the same line, or multiple conditional declarations using the same name.
+	The ID is not unique across different codes/files.
   - `\ast\parse_file` will now consistently return an empty statement list (similar to
     `\ast\parse_code`) if it is was passed a zero-byte file. Previously, it would return `null`.
  </notes>