Fix S4158 FN: Collection Expressions (C# 12)

[zsolt-kolbay-sonarsource]

Description

Collection expressions are not handled by the SE engine, leading to FNs like this:

Repro steps

List<int> emptyList = [];
emptyList.Clear();                  // FN

ReadOnlySpan<int> emptySpan = [.. emptyList];
foreach (int element in emptySpan)  // FN
{
    Console.WriteLine(element);
}

Expected behavior

S4158 raises a warning.

Actual behavior

No S4158 warnings are raised.

Related information

• C#/VB.NET Plugins version: 9.17
• Visual Studio version: Visual Studio 2022 (17.8.4)
• .NET version: 8.0
• Operating System: Windows 10

Implementation

With version 4.9.2 of Microsoft.CodeAnalysis.CSharp collection expressions are supported on the CFG level (previously it was always a NoneOperation).
A new Processor class is needed in the SE engine that can handle ICollectionExpressionOperation types (and also for ISpreadOperation).