[sanitizer-coverage] implement -fsanitize-coverage=trace-pc. This is similar to trace-bb, but has a different API. We already use the equivalent flag in GCC for Linux kernel fuzzing. We may be able to use this flag with AFL too

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@261159 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed