Ensure trailing comments on parameter declarations are consistent.

Author: kddnewton

CHANGELOG.md

@@ -38,6 +38,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) a
 - Explicitly handle `?"` so that it formats properly.
 - Check that a block is within the predicate in a more relaxed way.
 - Ensure the `Return` breaks with brackets and not parentheses.
+- Ensure trailing comments on parameter declarations are consistent.
 
 ### Removed
 

lib/syntax_tree.rb

@@ -8754,10 +8754,12 @@ def format(q)
       parts << KeywordRestFormatter.new(keyword_rest) if keyword_rest
       parts << block if block
 
-      q.nest(0) do
+      contents = -> {
         q.seplist(parts) { |part| q.format(part) }
         q.format(rest) if rest && rest.is_a?(ExcessedComma)
-      end
+      }
+
+      q.parent.is_a?(Paren) ? q.nest(0, &contents) : q.group(&contents)
     end
 
     def pretty_print(q)