Append missing version number to lldb binary built by cmake
- now, the output binary is called 'lldb-3.4' instead of 'lldb'
- a symlink 'lldb' -> 'lldb-3.4' is also created
- this fixes one of the problems preventing CMake from building Debian packages



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@182148 91177308-0d34-0410-b5e6-96231b3b80d8