fixes issue 642 + linux_drsyms sometimes needs to have two files open: symtab from   original library but dwarf from its .debug + don't look inside sh_type == SHT_NOBITS
fixes issue 642
+ linux_drsyms sometimes needs to have two files open: symtab from
  original library but dwarf from its .debug
+ don't look inside sh_type == SHT_NOBITS

SVN-Revision: 1197

AmesianX/dynamorio,AmesianX/dynamorio,code4bones/dynamorio,bl4ckic3/dynamorio,code4bones/dynamorio,code4bones/dynamorio,bl4ckic3/dynamorio,sigma-random/dynamorio,AmesianX/dynamorio,code4bones/dynamorio,bl4ckic3/dynamorio,daksunt/dynamorio,sigma-random/dynamorio,AmesianX/dynamorio,AmesianX/dynamorio,daksunt/dynamorio,bl4ckic3/dynamorio,daksunt/dynamorio,bl4ckic3/dynamorio,daksunt/dynamorio,sigma-random/dynamorio,sigma-random/dynamorio,daksunt/dynamorio,sigma-random/dynamorio,code4bones/dynamorio