[EventPipe] Fix folding constant warning

[mdh1418]

Fixes #120007

[Copilot]

Pull Request Overview

This PR fixes a folding constant warning in the EventPipe native code by replacing magic numbers with properly defined constants. The changes improve code maintainability by eliminating hardcoded values and making the code more readable.

Key changes:

• Defines new constants for EventPipe user events configuration
• Replaces magic numbers with named constants in session management code

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/native/eventpipe/ep-types-forward.h	Adds new constant definitions for user events capacity and activity ID extension size
src/native/eventpipe/ep-session.c	Replaces magic numbers with the newly defined constants

[mdh1418]

I upgraded my mac m1 to Tahoe 26.0.1 and Xcode 26.0.1 (17A400)

% sw_vers
ProductName: macOS
ProductVersion: 26.0.1
BuildVersion: 25A362

but I can't seem to reproduce the build errors @vcsjones hit in #120007 (comment) from a clean repo.

I think moving those vars to defines should resolve the warnings but as I can't repro the compiler warnings, I couldn't double check.

[vcsjones]

Hm. I still see the warnings in the build in main, but they no longer fail the build (did we change how this warning is treated somewhere?)

Anyway, I don't see the warnings in the build with this PR.

[lateralusX]

Putting the constant into a macro or enum should resolve the warning. Reduce the scope and put it directly in the source file instead of the more widely used header.