Several IL20XX trim warnings missed by analyzers, only show up with ILC

[Sergio0694]

Description

I've noticed several IL20XX trim warnings when publishing the Microsoft Store with NAOT, that only show up via ILC:

Reproduction Steps

Can't share repro steps here (since the code is not open source).
I can however share:

• binlog (MSFT only): link
• repo link and instructions to build locally (ping me on Teams)

Expected behavior

Ideally, all those warnings should also show up in the IDE.

Actual behavior

Several warnings only show up via ILC at publish time.

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Tagging subscribers to this area: @agocke, @sbomer, @vitek-karas
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[sbomer]

Simplified repro for the IL2091 warnings:

using System.Diagnostics.CodeAnalysis;

new C<string>().M();

class C<T> {
    public T M() {
        return G<T>.Factory.Create();
    }
}

class G<[DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.All)] T> {
    public static class Factory {
        public static T? Create() => default;
    }
}

The presence of the nested class is relevant.

[sbomer]

From what I can tell, all of the remaining extra warnings are expected:

• Some of the IL2026 warnings are for calls to RunClassConstructor of a type with RequiresUnreferencedCode. The class constructor is defined in a referenced assembly, so isn't visible to the analyzer. It's basically private reflection which the analyzer can't detect with the current semantics (though I would be interested in discussing different semantics).
• IL2087 was caught by the analyzer (in a different Csc invocation)
• IL2050 was produced for an assembly that wasn't built as part of this project

However, I noticed in the local repro that the analyzer was producing extra IL2059 warnings compared to ILC for RunClassConstructor of an enum: #109429