marshal.c: revert r57631 partially
* marshal.c (rb_marshal_dump_limited): do not free dump_arg, which
may be dereferenced in check_dump_arg due to continuation, and
get rid of dangling pointers.
* marshal.c (rb_marshal_load_with_proc): ditto for load_arg.
merge revision(s) 57634: [Backport #13150]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_3@59551 b2dd03c8-39d4-4d8f-98ff-823fe69b080e