Null-conditional LINQ chain over a value type is emitted as invalid query syntax (CS1936)

[sailro]

Input code

using System.Collections.Immutable;
using System.Linq;

public sealed class Box
{
	public ImmutableArray<int> Values { get; init; }
}

public static class C
{
	public static string? FirstPositive(Box? box) =>
		box?.Values
			.Where(value => value > 0)
			.Select(value => value.ToString())
			.FirstOrDefault();
}

Erroneous output

public static string? FirstPositive(Box? box)
{
	return (from value in box?.Values
		where value > 0
		select value.ToString()).FirstOrDefault();
}

This does not compile:

error CS1936: Could not find an implementation of the query pattern for source type 'ImmutableArray<int>?'

The null-conditional access lifts Values to ImmutableArray<int>?. The method chain must remain inside the conditional access.

Details

Product: ICSharpCode.Decompiler / ilspycmd.

Version: master 9ea8d7c.

The input was compiled in Release for net10.0.

I can submit a small fix and regression test.