[main] Source code updates from dotnet/source-build-reference-packages

[dotnet-maestro]

Note

This is a codeflow update. It may contain both source code changes from
the source repo
as well as dependency updates. Learn more here.

This pull request brings the following source code changes

From https://github.com/dotnet/source-build-reference-packages

• Subscription: a489221b-e15f-400c-b9df-232e2eb2f68b
• Build: 20260306.2 (304880)
• Date Produced: March 6, 2026 2:29:18 PM UTC
• Commit: 126ae71663e3d22030fc7e55d71ead23d140432d
• Commit Diff: fada075...126ae71
• Branch: main

Diff the source with this PR branch

darc vmr diff --name-only https://github.com/dotnet/source-build-reference-packages:126ae71663e3d22030fc7e55d71ead23d140432d..https://github.com/dotnet/dotnet:darc-main-e703f000-fa75-4834-a3ce-3e1078e5b6fd

[dotnet-maestro]

Note

PRs from original repository included in this codeflow update:

• [main] Source code updates from dotnet/dotnet source-build-assets#1586
• [main] Source code updates from dotnet/dotnet source-build-assets#1588
• [main] Source code updates from dotnet/dotnet source-build-assets#1590
• Add external antlr4 project source-build-assets#1585

💡 You may consult the FAQ for more information or tag @dotnet/prodconsvcs for assistance.

[am11]

LGTM