Added a simple legend to the unit test 'dots' output, to aid understandability.

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@191398 91177308-0d34-0410-b5e6-96231b3b80d8
Changed fuzz tests to not print their values (we only need to test if access to them does not crash).
This fixes the 'No value' string appearing in the dotest results.

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@191399 91177308-0d34-0410-b5e6-96231b3b80d8