IModule should implement ISymbol.

ICSharpCode.Decompiler/TypeSystem/IAssembly.cs

@@ -45,7 +45,7 @@ namespace ICSharpCode.Decompiler.TypeSystem
 	/// <summary>
 	/// Represents a metadata module.
 	/// </summary>
-	public interface IModule : ICompilationProvider
+	public interface IModule : ISymbol, ICompilationProvider
 	{
 		/// <summary>
 		/// Gets the underlying metadata file. May return null, if the IAssembly was not created from a PE file.

ICSharpCode.Decompiler/TypeSystem/ISymbol.cs

@@ -21,6 +21,8 @@ namespace ICSharpCode.Decompiler.TypeSystem
 	public enum SymbolKind : byte
 	{
 		None,
+		/// <seealso cref="IModule"/>
+		Module,
 		/// <seealso cref="ITypeDefinition"/>
 		TypeDefinition,
 		/// <seealso cref="IField"/>

ICSharpCode.Decompiler/TypeSystem/Implementation/MinimalCorlib.cs

@@ -53,6 +53,8 @@ namespace ICSharpCode.Decompiler.TypeSystem.Implementation
 
 		string IModule.AssemblyName => "corlib";
 		string IModule.FullAssemblyName => "corlib";
+		string ISymbol.Name => "corlib";
+		SymbolKind ISymbol.SymbolKind => SymbolKind.Module;
 
 		Metadata.PEFile IModule.PEFile => null;
 		INamespace IModule.RootNamespace => rootNamespace;

ICSharpCode.Decompiler/TypeSystem/MetadataModule.cs

@@ -92,6 +92,8 @@ namespace ICSharpCode.Decompiler.TypeSystem
 
 		public string AssemblyName { get; }
 		public string FullAssemblyName { get; }
+		string ISymbol.Name => AssemblyName;
+		SymbolKind ISymbol.SymbolKind => SymbolKind.Module;
 
 		public INamespace RootNamespace => rootNamespace;