Add Regex.EnumerateSplits

[stephentoub]

Closes #100369

[dotnet-issue-labeler]

Note regarding the new-api-needs-documentation label:

This serves as a reminder for when your PR is modifying a ref *.cs file and adding/modifying public APIs, please make sure the API implementation in the src *.cs file is documented with triple slash comments, so the PR reviewers can sign off that change.

[dotnet-issue-labeler]

Note regarding the new-api-needs-documentation label:

This serves as a reminder for when your PR is modifying a ref *.cs file and adding/modifying public APIs, please make sure the API implementation in the src *.cs file is documented with triple slash comments, so the PR reviewers can sign off that change.

[joperezr]

Couple of questions but looks great. Thanks Steve!

[colejohnson66]

I know this is already merged, but shouldn't startat be startAt?

[stephentoub]

I know this is already merged, but shouldn't startat be startAt?

If we were starting from scratch, yes, but this is how all the other regex methods spell it, e.g. https://learn.microsoft.com/en-us/dotnet/api/system.text.regularexpressions.regex.match?view=net-8.0#system-text-regularexpressions-regex-match(system-string-system-int32), so we're staying consistent with that.