run: use a "named namespace" also for the main option parser

run: use a "named namespace" also for the main option parser

It seems that clang reorders the entries in the options array that
originate from different functions, but not within a function. Using
"named namespaces" exclusively should sidestep the issue.

(A bigger hammer would be to sort the array. We *can* do this, since the
options have the increasing .id field. But that'd require duplicating
the memory or making it writable. Let's avoid this until we know for
sure that it's needed.)