[parrot/parrot] d84472: [pmc] disable 2x StringBuilder.substr clone, GH #1...

[GitHub]

  Branch: refs/heads/rurban/stringbuilder-gh1123
  Home:   https://github.com/parrot/parrot
  Commit: d84472c60fa8e4a97572d9368b923a2ffde94550
      https://github.com/parrot/parrot/commit/d84472c60fa8e4a97572d9368b923a2ffde94550
  Author: Reini Urban <rurban at cpanel.net>
  Date:   2015-01-21 (Wed, 21 Jan 2015)

  Changed paths:
    M src/pmc/stringbuilder.pmc

  Log Message:
  -----------
  [pmc] disable 2x StringBuilder.substr clone, GH #1123

STRING_substr already creates a copy for us, no need to copy it twice.
no regression.

Note that t/stress/gc.t started failing earlier, even in 7.0.0.