errdefer and try/defer fix

compiler/ast/ast.odin

@@ -169,6 +169,7 @@ Stmt :: struct {
 	immutable:  bool,
 	value_control_flow: bool,
 	pointer_capture: bool,
+	error_only: bool,
 	// Assignments store the lvalue in `target`, the right-hand side in `expr`,
 	// and the source operator in `assignment_op`. `Set` is ordinary `=`;
 	// the arithmetic variants are `+=`, `-=`, `*=`, and `/=`.
@@ -187,7 +188,8 @@ Stmt :: struct {
 	// distinguish `|@item|` from copy capture.
 	// `Block` statements (a bare `{ ... }` scope) use `body` as their statements.
 	// `Defer` statements use `update` as the deferred statement (which may itself
-	// be a `Block`).
+	// be a `Block`), `error_only` for `errdefer`, and `captures` for its optional
+	// error capture.
 	// `Match` statements use `expr` as the subject and `body` as the list of arm
 	// statements (each a `Match_Arm`). A `Match_Arm` uses `patterns` as its pattern
 	// list (empty marks the `else` arm; more than one is a multi-pattern arm),