Pullup ticket #3841 - requested by tron
net/libtorrent build fix

Revisions pulled up:
- net/libtorrent/Makefile                                      1.45

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  Module Name: pkgsrc
  Committed By: tron
  Date: Mon Jul  2 07:01:52 UTC 2012

  Modified Files:
  pkgsrc/net/libtorrent: Makefile

  Log Message:
  Compile with GCC option "-march=i486" on x86 systems to make the required
  function "__sync_bool_compare_and_swap_4" available. This fixes the build
  of the "rtorrent" package under NetBSD/i386 5.1_STABLE.

(sbd)