Add [DebuggerStepThrough] to ArgumentNullException.ThrowIfNull

[scoraig52]

Problem

When debugging with .NET Framework source stepping enabled, F11 steps into ArgumentNullException.ThrowIfNull on null input, breaking debugger flow.

Expected: Step through user's if (input == null) or skip via [DebuggerStepThrough]
Actual: Steps into framework source

Reproduction

1. Enable "Enable .NET Framework source stepping" in VS Options
2. F11 on ArgumentNullException.ThrowIfNull(input, nameof(input))
3. Debugger enters framework method

Proposed Fix

[DebuggerStepThrough]
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static void ThrowIfNull([NotNull] object? argument, string? paramName = null)

[jeffschwMSFT]

please create an issue on https://developercommunity.visualstudio.com/home and link back to this issue. we track .NET Framework requests there. thanks

[tannergooding]

@jeffschwMSFT, this isn't a .NET Framework request, it's about the debugger option in VS named .NET Framework Source Stepping which applies to all of .NET

ArgumentNullException.ThrowIfNull is a .NET 7+ only API

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[tannergooding]

That being said, @scoraig52 you have both "Just my code" disabled and ".NET Framework Source Stepping" enabled, so this is behaving exactly as intended and designed today.

We had previously discussed a similar situation with StackTraceHidden as part of #90539 and it has been a contentious point with input from @stephentoub, @jkotas, and others. The topic of DebuggerHidden had also come up as part of this.

Without that being resolved, I don't think there's anything to be done for this issue and this one can likely be closed as a duplicate of #90539. It is, however, another datapoint that is given a general +1 to the idea that the broader community does not want to see or be able to step through these "trivial throw helpers" (of which previous polling and community input was already largely in favor of the change).