[lsan] Make the report_objects flag more useful.

Print the list of leaked objects after each leak report. Previously we
printed only a joint list of all leaked objects. As a bonus, suppressed objects
are no longer reported.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@197977 91177308-0d34-0410-b5e6-96231b3b80d8