[main] optparse: allow multiple repeated options

[silverweed]

This Pull request:

Allows specifying that an option may appear multiple times in optparse.hxx, and allows retrieving all its values.

[dpiparo]

Thanks. Could you perhaps give some details relative to the use case that this feature will unblock?

[silverweed]

Thanks. Could you perhaps give some details relative to the use case that this feature will unblock?

It's to investigate if we can use this option parsing to replace rootcling's current one, which has some issues related to the LLVM option parsing code (@hahnjo and @devajithvs have more details, but it's something we're gonna look at next year - no need to merge it now)

[github-actions]

Test Results

    21 files      21 suites   3d 17h 10m 47s ⏱️
 3 787 tests  3 786 ✅ 0 💤 1 ❌
77 707 runs  77 706 ✅ 0 💤 1 ❌

For more details on these failures, see this check.

Results for commit d6d6b43.