Support getting executable's name for sanitizers needs on FreeBSD

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@209805 91177308-0d34-0410-b5e6-96231b3b80d8
[ASan Win tests] Add a couple more memcpy/memset tests

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@209806 91177308-0d34-0410-b5e6-96231b3b80d8