VSTHRD010 triggers on method defining delegates that require the main thread

Bug description

It seems like VSTHRD010 will flag methods that define delegates that call ThreadHelper.ThrowIfNotOnUIThread, though the method itself does not invoke the delegate.

Repro steps

abstract class Foo
{
    Foo()
    {
        this.RefreshCommand = new RelayCommand(
            execute: (object param) => { ThreadHelper.ThrowIfNotOnUIThread(); StartForceRefreshRequest(param); }
            canExecute: (_) => { ThreadHelper.ThrowIfNotOnUIThread(); return CanExecuteForceRefreshCommand(); }
        );
    }
}

class Bar : Foo
{
    Bar() : base()
    {
        // analyzer flags this constructor with the warning:
        // VSTHRD010: Accessing "Foo..ctor" should only be done on the main thread
    }
}

Expected behavior

No threading analyzer warning for the described case.

Actual behavior

Threading analyzer fires warning.

• Version used: latest (v17.11.20)

Additional context

I have not extensively verified the exact conditions for this, but I have verified that removing the thread-affinitized delegate prevents the analyzer warning.

Start by reproducing the VSTHRD010 warning from the constructor and delegate example in the issue, then trace the analyzer's handling of thread-affinitized delegate bodies. Done means the constructor no longer receives a warning when it only defines delegates that call ThreadHelper.ThrowIfNotOnUIThread, while genuine main-thread access remains diagnosed.