[release/8.0] Revert "Workaround a C++/CLI bug involving DIMs (#89253)"

[github-actions]

Backport of #92234 to release/8.0

/cc @jeffhandley @tannergooding

Customer Impact

Earlier during .NET 8, we implemented Ensure that INumberBase implements IUtf8SpanFormattable by tannergooding · Pull Request #88840 · dotnet/runtime as part of introducing IUtf8SpanFormattable, implementing that interface on INumberBase. This implementation introduced a pattern for default interface methods that we hadn't previously employed, and it surfaced a C++/CLI issue that ultimately blocked builds of dotnet/wpf.

To unblock the dotnet/wpf builds, we merged Workaround a C++/CLI bug involving DIMs by tannergooding · Pull Request #89253 · dotnet/runtime and prepared the Revert "Workaround a C++/CLI bug involving DIMs (#89253)" by tannergooding · Pull Request #92234 · dotnet/runtime PR as well.

The C++/CLI issue was fixed in VS 17.8.0 Preview 2, which is now rolled out into our engineering systems and underlies the dotnet/wpf builds. With that in place, we've merged #92234 and this backports that revert into release/8.0, ensuring we have the desired API shape within the .NET 8 release.

Testing

As part of preparing #92234, we verified that the C++/CLI issue is fixed in VS 17.8.0 Preview 2 and our default interface method approach does not cause build breaks for dotnet/wpf.

Risk

Low. We did not observe anything else having trouble with this interface implementation approach. But we will monitor code flow for both main and release/8.0.

[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.

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Issue Details

---

Backport of #92234 to release/8.0

/cc @jeffhandley @tannergooding

Customer Impact

Testing

Risk

IMPORTANT: If this backport is for a servicing release, please verify that:

• The PR target branch is release/X.0-staging, not release/X.0.

• If the change touches code that ships in a NuGet package, you have added the necessary package authoring and gotten it explicitly reviewed.

Author:	github-actions[bot]
Assignees:	-
Labels:	area-System.Numerics, new-api-needs-documentation
Milestone:	-