[libFuzzer] Merge: print stats after reading the output corpus dir.

The purpose is to be able to extract the number of new edges added to
the original (i.e. output) corpus directory after doing the merge. Use case
example: in ClusterFuzz, we do merge after every fuzzing session, to avoid
uploading too many corpus files, and we also record coverage stats at that
point. Having a separate line indicating stats after reading the initial output
corpus directory would make the stats extraction easier for both humans and
parsing scripts.

Context: https://github.com/google/clusterfuzz/issues/802.

Reviewers: morehouse, hctim

Reviewed By: hctim

Subscribers: delcypher, #sanitizers, llvm-commits, kcc

Tags: #llvm, #sanitizers

Differential Revision: https://reviews.llvm.org/D66020

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk/lib/fuzzer@368461 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed