* vm_args.c (refine_sym_proc_call): resolve refinements when the
  proc is invoked, instead of resolving at making the proc, to
  enable refinements on symbol-proc in ruby-level methods

* vm.c (vm_cref_dup): clear cached symbol-procs when duplicating.

[Bug #15114] [Fix GH-2039]

From: manga_osyo <manga.osyo@gmail.com>

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66439 b2dd03c8-39d4-4d8f-98ff-823fe69b080e