[gold patch] Fix incremental update with comdat sections

[Cary Coutant]

>> 2011-09-12  Cary Coutant  <ccoutant@google.com>
>>
>>       * incremental.cc (Sized_relobj_incr::do_layout): Call
>>       report_comdat_group for kept comdat sections.
>>       * testsuite/Makefile.am (incremental_comdat_test_1): New test.
>>       * testsuite/Makefile.in: Regenerate.
>>       * testsuite/incr_comdat_test_1.cc: New source file.
>>       * testsuite/incr_comdat_test_2_v1.cc: New source file.
>>       * testsuite/incr_comdat_test_2_v2.cc: New source file.
>>       * testsuite/incr_comdat_test_2_v3.cc: New source file.
>
> This is OK.

Thanks, committed.

-cary