message: [CMake] Remove check for the readline target.
  This was introduced when we were building a custom readline Python
  module on Linux [1]. Now that the readline  target doesn't exist
  anymore, it's safe to remove this dependency.
  This fixes
  [1]
diff: @@ -209,10 +209,7 @@ if (NOT LLDB_DISABLE_PYTHON)
  DEPENDS ${lldb_scripts_dir}/lldb.py
  COMMENT "Python script sym-linking LLDB Python API")
  - if (TARGET readline)
  - set(readline_dep readline)
  - endif()
  - add_dependencies(finish_swig swig_wrapper liblldb lldb-argdumper ${readline_dep})
  + add_dependencies(finish_swig swig_wrapper liblldb lldb-argdumper)
  set_target_properties(finish_swig swig_wrapper PROPERTIES FOLDER "lldb misc")
  # Ensure we do the python post-build step when building lldb.
  