Connect up the Mach-O reader to the new DiImage abstractions.


git-svn-id: svn://svn.valgrind.org/valgrind/branches/DISRV@13430 a5019735-40e9-0310-863c-91ae7b9d1cf9
Minimal changes needed to make this suitable for trunk:

* add a new flag --allow-mismatched-debuginfo to override the
  CRC32/build-id checks, if needed

* tidy up logic for finding files on the --extra-debuginfo-path
  and at the --debuginfo-server

* don't assert if connection to the debuginfo server is lost;
  instead print a reasonable message and quit.



git-svn-id: svn://svn.valgrind.org/valgrind/branches/DISRV@13431 a5019735-40e9-0310-863c-91ae7b9d1cf9
Exit a bit more gracefully if a request to get part of an image
exceeds the allowable range.  With this change, it should be
essentially impossible to crash V by feeding it invalid ELF or Dwarf.



git-svn-id: svn://svn.valgrind.org/valgrind/branches/DISRV@13432 a5019735-40e9-0310-863c-91ae7b9d1cf9
Make the ppc64-linux .opd-reading machinery work in the new framework.


git-svn-id: svn://svn.valgrind.org/valgrind/branches/DISRV@13434 a5019735-40e9-0310-863c-91ae7b9d1cf9