[lldb] Make lldb-argdumper a dependency of liblldb

Always make lldb-argdumper a dependency of liblldb. Currently it is only
a dependency of the python swig target because of the relative symlink
in the python resource directory. That means that the dependency won't
be there when LLDB_ENABLE_PYTHON is disabled.

Differential revision: https://reviews.llvm.org/D86722