[libFuzzer] explicitly use -fsanitize-coverage=trace-pc-guard in test/dump_coverage.test; mark print_coverage/dump_coverage as To-be-deprecated

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@310877 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed