[lldb][swig] Fix autodocs flag parsing

r366471 added "-features autodoc" without a trailing comment, leading to `Unrecognized option -features autodoc-threads` due to implicit string concatenation. Add a comma to fix that.

Also separate into "-features" and "autodoc", otherwise it gets parsed as a single "-features autodoc" flag which is also not recognized (it must be two separate CLI args).

llvm-svn: 366478