* .gdbinit (iseq): rename dummy_gdb_enums to ruby_dummy_gdb_enums.
  This is follow up to changes in r24407.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_0_0@39570 b2dd03c8-39d4-4d8f-98ff-823fe69b080e