Incorrect stack trace line number when exception originates inside a `foreach` loop body over an iterator method in Release configuration

[Liangjia0411]

Description

When an exception is thrown inside a foreach loop that iterates over an IEnumerable<T> implemented with yield return, the stack trace points to the foreach line instead of the actual line that caused the exception. This only happens in Release builds; Debug builds report the correct line number.

Steps to Reproduce

1. Create a new .NET 9 console application.
2. Replace Program.cs with the following code:

namespace TestNamespace
{
    public class Program
    {
        public static void Main(string[] args)
        {
            StackDumpTest();
        }

        class HeroInfo
        {
            public string skill;
            public HeroInfo(string s) { skill = s; }
        }

        static IEnumerable<HeroInfo> GetAllHeroes()
        {
            yield return new HeroInfo("1");
            yield return new HeroInfo(null!);   // deliberately null string
            yield return new HeroInfo("2");
        }

        public static void StackDumpTest()
        {
            foreach (var heroInfo in GetAllHeroes())
            {
                Console.WriteLine(heroInfo.skill.Length);   // this is line 27
            }
        }
    }
}

3. Build and run in Release mode (e.g., dotnet run -c Release).
4. Observe the stack trace in the console output.

Expected Behavior

The NullReferenceException thrown because of heroInfo.skill.Length (where skill is null) should be reported at line 27 (the line inside the loop body where .Length is accessed).

Actual Behavior

The stack trace reports the exception at line 25 (the foreach line), which is misleading:

Unhandled exception. System.NullReferenceException: Object reference not set to an instance of an object.
   at TestNamespace.Program.StackDumpTest() in E:\...\Program.cs:line 25
   at TestNamespace.Program.Main(String[] args) in E:\...\Program.cs:line 7

Additional Information

• .NET Version: .NET 9.0 (Release build, win-x64)
• OS: Windows (x64)
• This problem does not occur in Debug builds (where line 27 is correctly reported).
• The issue seems specific to the interaction between yield return (iterator state machine) and PDB/sequence point information in release-optimized code.

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