Add crash report support to the CrashDump extension

[Copilot]

New Feature

What does this feature do?

The CrashDump extension can now ask the .NET runtime to generate JSON crash reports in addition to, or instead of, a dump. This makes crash triage lighter-weight in CI, especially for environments where full dump collection is expensive or impractical.

Why is this feature needed?

DOTNET_EnableCrashReport and DOTNET_EnableCrashReportOnly are already available in the runtime, but the MTP CrashDump extension only exposed dump generation. Surfacing crash reports gives a cheaper diagnostic path and improves crash investigation on machines where developers cannot inspect native dumps directly.

Implementation details

• CLI surface

  • Added --crashreport to generate a crash report alongside --crashdump
  • Added --crashreport-only to request only the JSON crash report
  • Added validation for invalid combinations:
    • --crashreport requires --crashdump
    • --crashreport-only cannot be combined with other crash options

• Runtime configuration

  • Wired the new options to the runtime environment variables:
    • DOTNET_EnableCrashReport
    • DOTNET_EnableCrashReportOnly
  • Kept DbgEnableMiniDump enabled for --crashreport-only, since the runtime still requires createdump activation to emit the report

• Artifacts and user-visible behavior

  • Added crash report artifact discovery/publishing for *.crashreport.json
  • Updated crash messages to distinguish:
    • dump only
    • report only
    • dump + report
  • Updated help text and package docs to describe the new options

• Coverage

  • Extended unit coverage for command-line validation
  • Added acceptance coverage for:
    • dump + crash report
    • crash report only
    • invalid --crashreport usage
  • Updated help/info expectations for the new CLI options

Example

# Generate a dump and a JSON crash report
dotnet test -- --crashdump --crashreport

# Generate only a JSON crash report
dotnet test -- --crashreport-only