Fold DoBlock and BraceBlock into Block

Author: kddnewton

CHANGELOG.md

@@ -16,6 +16,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) a
   - `FCall` is no longer a node. Instead it has been folded into the `Call` node. The `Call` node can now have its `receiver` and `operator` fields be `nil`. Consequently, the `visit_fcall` method has been removed from the visitor interface. If you were previously using this method, you should now use `visit_call` instead.
   - `Dot2` and `Dot3` are no longer nodes. Instead they have become a single new `RangeLiteral` node. This node looks the same as `Dot2` and `Dot3`, except that it additionally has an `operator` field that contains the operator that created the node. Consequently, the `visit_dot2` and `visit_dot3` methods have been removed from the visitor interface. If you were previously using these methods, you should now use `visit_range_literal` instead.
   - `DefEndless` and `Defs` have both been folded into the `Def` node. The `Def` node now has the `target` and `operator` fields which originally came from `Defs` which can both be `nil`. It also now has an `endless?` method on it to tell if the original node was found in the endless form. Finally the `bodystmt` field can now either be a `BodyStmt` as it was or any other kind of node since that was the body of the `DefEndless` node. The `visit_defs` and `visit_def_endless` methods on the visitor have therefore been removed.
+  - `DoBlock` and `BraceBlock` have now been folded into a `Block` node. The `Block` node now has a `keywords?` method on it that returns true if the block was constructed with the `do`..`end` keywords. The `visit_do_block` and `visit_brace_block` methods on the visitor have therefore been removed and replaced with the `visit_block` method.
 
 ## [4.3.0] - 2022-10-28