Compilation with module initializer fails

[aelij]

Version Used: 4.0.0-4.final, .NET 5.0.10

Steps to Reproduce:

using System;
using System.IO;
using System.Linq;
using System.Runtime.Loader;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;

const string ModuleInit = @"
            internal static class ModuleInitializer
            {
                [System.Runtime.CompilerServices.ModuleInitializer]
                internal static void Initialize() =>
                    System.Console.WriteLine(2);
            }
        ";

const string Code = "System.Console.WriteLine(1);";

var compilation = CSharpCompilation.Create(
    "test",
    new[]
    {
        SyntaxFactory.ParseSyntaxTree(ModuleInit),
        SyntaxFactory.ParseSyntaxTree(Code)
    },
    references: AssemblyLoadContext.Default.Assemblies
        .Where(a => a.FullName.Contains("System"))
        .Select(a => MetadataReference.CreateFromFile(a.Location)));

using var peStream = File.OpenWrite("test.dll");
using var pdbStream = File.OpenWrite("test.pdb");
try
{
    var emitResult = compilation.Emit(
        peStream: peStream,
        pdbStream: pdbStream);
}
catch (Exception ex)
{
    Console.WriteLine(ex);
}

Expected Behavior:
Compilation succeeds.

Actual Behavior:

System.InvalidOperationException: This program location is thought to be unreachable.
   at Microsoft.Cci.RootModuleType.Microsoft.Cci.INamespaceTypeReference.GetUnit(EmitContext context)
   at Microsoft.Cci.MetadataWriter.GetDefiningUnitReference(ITypeReference typeReference, EmitContext context)
   at Microsoft.Cci.MetadataWriter.GetMethodHandle(IMethodReference methodReference)
   at Microsoft.Cci.PdbWriter.SerializeDebugInfo(IMethodBody methodBody, StandaloneSignatureHandle localSignatureHandleOpt, CustomDebugInfoWriter customDebugInfoWriter)
   at Microsoft.Cci.MetadataWriter.SerializeMethodBodies(BlobBuilder ilBuilder, PdbWriter nativePdbWriterOpt, Blob& mvidStringFixup)
   at Microsoft.Cci.MetadataWriter.BuildMetadataAndIL(PdbWriter nativePdbWriterOpt, BlobBuilder ilBuilder, BlobBuilder mappedFieldDataBuilder, BlobBuilder managedResourceDataBuilder, Blob& mvidFixup, Blob& mvidStringFixup)
   at Microsoft.Cci.PeWriter.WritePeToStream(EmitContext context, CommonMessageProvider messageProvider, Func`1 getPeStream, Func`1 getPortablePdbStreamOpt, PdbWriter nativePdbWriterOpt, String pdbPathOpt, Boolean metadataOnly, Boolean isDeterministic, Boolean emitTestCoverageData, Nullable`1 privateKeyOpt, CancellationToken cancellationToken)
   at Microsoft.CodeAnalysis.Compilation.SerializePeToStream(CommonPEModuleBuilder moduleBeingBuilt, DiagnosticBag metadataDiagnostics, CommonMessageProvider messageProvider, Func`1 getPeStream, Func`1 getMetadataPeStreamOpt, Func`1 getPortablePdbStreamOpt, PdbWriter nativePdbWriterOpt, String pdbPathOpt, RebuildData rebuildData, Boolean metadataOnly, Boolean includePrivateMembers, Boolean isDeterministic, Boolean emitTestCoverageData, Nullable`1 privateKeyOpt, CancellationToken cancellationToken)
   at Microsoft.CodeAnalysis.Compilation.SerializeToPeStream(CommonPEModuleBuilder moduleBeingBuilt, EmitStreamProvider peStreamProvider, EmitStreamProvider metadataPEStreamProvider, EmitStreamProvider pdbStreamProvider, RebuildData rebuildData, Func`2 testSymWriterFactory, DiagnosticBag diagnostics, EmitOptions emitOptions, Nullable`1 privateKeyOpt, CancellationToken cancellationToken)
   at Microsoft.CodeAnalysis.Compilation.Emit(Stream peStream, Stream metadataPEStream, Stream pdbStream, Stream xmlDocumentationStream, Stream win32Resources, IEnumerable`1 manifestResources, EmitOptions options, IMethodSymbol debugEntryPoint, Stream sourceLinkStream, IEnumerable`1 embeddedTexts, RebuildData rebuildData, CompilationTestData testData, CancellationToken cancellationToken)
   at Microsoft.CodeAnalysis.Compilation.Emit(Stream peStream, Stream pdbStream, Stream xmlDocumentationStream, Stream win32Resources, IEnumerable`1 manifestResources, EmitOptions options, IMethodSymbol debugEntryPoint, Stream sourceLinkStream, IEnumerable`1 embeddedTexts, Stream metadataPEStream, RebuildData rebuildData, CancellationToken cancellationToken)   at Microsoft.CodeAnalysis.Compilation.Emit(Stream peStream, Stream pdbStream, Stream xmlDocumentationStream, Stream win32Resources, IEnumerable`1 manifestResources, EmitOptions options, IMethodSymbol debugEntryPoint, Stream sourceLinkStream, IEnumerable`1 embeddedTexts, Stream metadataPEStream, CancellationToken cancellationToken)
   at Program.<Main>$(String[] args) in Program.cs:line 34

[RikkiGibson]

Looks like duplicate of #56412.

[RikkiGibson]

Closing the issue since it appears to be a duplicate of a solved issue. Thank you for reporting. If you feel there's been a mistake, feel free to follow up or reopen the issue.