[ruby/irb] Ensure to restore $VERBOSE

https://github.com/ruby/irb/commit/cef474a76a

lib/irb/color.rb

@@ -192,6 +192,7 @@ module IRB # :nodoc:
             end
           end
         end
+      ensure
         $VERBOSE = verbose
       end
 

lib/irb/ruby-lex.rb

@@ -139,8 +139,9 @@ class RubyLex
         tokens = lexer.parse
       end
     end
-    $VERBOSE = verbose
     tokens
+  ensure
+    $VERBOSE = verbose
   end
 
   def find_prev_spaces(line_index)