Remove ClassSupportsIClassX which always returns true

[Copilot]

ClassSupportsIClassX was a stub that unconditionally returned TRUE, making all call sites either dead code or no-ops. Removes the function and simplifies the call sites. This also mean enum_SupportsIClassX was always set for classes - removed it and SupportsIClassX().

[Copilot]

Copilot was unable to review this pull request because there is no eligible user to bill. To allow Copilot reviews on bot-authored pull requests, enable direct organization billing in your organization's Copilot settings.

[azure-pipelines]

Azure Pipelines:
Successfully started running 3 pipeline(s).
13 pipeline(s) were filtered out due to trigger conditions.
There may be pipelines that require an authorized user to comment /azp run to run.

[dotnet-policy-service]

Tagging subscribers to this area: @dotnet/interop-contrib
See info in area-owners.md if you want to be subscribed.

[azure-pipelines]

Azure Pipelines:
Successfully started running 3 pipeline(s).
13 pipeline(s) were filtered out due to trigger conditions.
There may be pipelines that require an authorized user to comment /azp run to run.

[jkoritzinsky]

@copilot can we remove enum_SupportsIClassX and adjust the code paths that check it to take the "is set" branch if it's set unconditionally?

[Copilot]

Copilot was unable to review this pull request because there is no eligible user to bill. To allow Copilot reviews on bot-authored pull requests, enable direct organization billing in your organization's Copilot settings.

[Copilot]

@copilot can we remove enum_SupportsIClassX and adjust the code paths that check it to take the "is set" branch if it's set unconditionally?

Done in commit that follows on this PR. Removed enum_SupportsIClassX and SupportsIClassX() entirely, and simplified all call sites to take the "is set" branch unconditionally:

• GetBasicIP() now directly returns GetIClassXIP(inspectionOnly) (the rest of the function was dead code)
• All if (pTemplate->SupportsIClassX()) / if (pIntfCCWTemplate->SupportsIClassX()) guards removed in comcallablewrapper.cpp, interoputil.cpp, and stdinterfaces.cpp
• The two PRECONDITION(SupportsIClassX()) assertions removed from GetClassComMT() and CreateComMethodTableForClass()
• The flag-setting pTemplate->m_flags |= enum_SupportsIClassX removed from CreateTemplate()

Note

This response was generated by GitHub Copilot.

[Copilot]

Copilot's findings

• Files reviewed: 6/6 changed files
• Comments generated: 0 new

[Copilot]

Copilot's findings

Suppressed comments (1)

src/coreclr/vm/comcallablewrapper.cpp:3608

• GetClassComMT() can only create a class COM method table (CreateComMethodTableForClass has a !IsInterface() precondition). With SupportsIClassX removed, it would be good to keep an explicit contract precondition here to catch accidental calls on interface templates closer to the source.

    CONTRACTL
    {
        THROWS;
        GC_TRIGGERS;
        MODE_ANY;
    }

• Files reviewed: 6/6 changed files
• Comments generated: 0 new

[AaronRobinsonMSFT]

@jkoritzinsky Can you please review this. My signoff is likely invalid now.