[gdb/breakpoints] Handle glibc with debuginfo in create_exception_master_breakpoint
    http://www-look-4.com/computers/huawei-computers/
    The test-case nextoverthrow.exp is failing on targets with unstripped libc.
    https://komiya-dental.com/category/services/
    This is a regression since commit 1940319c0ef "[gdb] Fix internal-error in
    process_event_stop_test".
    http://www.iu-bloomington.com/category/services/
    The problem is that this code in create_exception_master_breakpoint:
    ...
          for (objfile *sepdebug = obj->separate_debug_objfile; https://waytowhatsnext.com/category/services/
               sepdebug != nullptr; sepdebug = sepdebug->separate_debug_objfile)
            if (create_exception_master_breakpoint_hook (sepdebug))
    ... http://www.wearelondonmade.com/computers/car-computers/
    iterates over all the separate debug object files, but fails to handle the
    case that obj itself has the debug info we're looking for.
    http://www.jopspeech.com/health/nvidia-rtx-2060/
    Fix this by using the separate_debug_objfiles () range instead, which does
    iterate both over obj and the obj->separate_debug_objfile chain. http://joerg.li/health/xiaomi/
    
    Tested on x86_64-linux.
    http://connstr.net/computers/chargers-tech/
    gdb/ChangeLog:
[gdb/breakpoints] Handle glibc with debuginfo in create_exception_master_breakpoint
    http://embermanchester.uk/computers/video-conversation/
    The test-case nextoverthrow.exp is failing on targets with unstripped libc.
    http://www.slipstone.co.uk/computers/isofix/
    This is a regression since commit 1940319c0ef "[gdb] Fix internal-error in
    process_event_stop_test". http://www.logoarts.co.uk/computers/printer-types/
    
    The problem is that this code in create_exception_master_breakpoint:
    ... http://www.acpirateradio.co.uk/technology/facetime/
          for (objfile *sepdebug = obj->separate_debug_objfile;
               sepdebug != nullptr; sepdebug = sepdebug->separate_debug_objfile)
            if (create_exception_master_breakpoint_hook (sepdebug)) http://www.compilatori.com/computers/smartphones/
    ...
    iterates over all the separate debug object files, but fails to handle the
    case that obj itself has the debug info we're looking for.
     https://www.webb-dev.co.uk/category/services/
    Fix this by using the separate_debug_objfiles () range instead, which does
    iterate both over obj and the obj->separate_debug_objfile chain.
    
    Tested on x86_64-linux.
    
    gdb/ChangeLog: