[LibFuzzer] Introducing FUZZER_FLAG_UNSIGNED and using it for seeding.

Differential Revision: http://reviews.llvm.org/D15339

done

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@255296 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed