common.mk: keep verconf.h if unchanged

* common.mk (verconf.h): update only when changed to reduce
  unnecessary recompiling loadpath.c.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48536 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
dummyparser.rb: on_rescue

* test/ripper/dummyparser.rb (on_rescue): add to turn exception
  class list into NodeList, to test exception class list.

* test/ripper/test_parser_events.rb (test_rescue_class): add
  missing test.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48537 b2dd03c8-39d4-4d8f-98ff-823fe69b080e