Implement more APIs in new TypeBuilder, fix bugs found during testing

src/libraries/System.Reflection.Emit/src/Resources/Strings.resx

@@ -258,4 +258,10 @@
   <data name="InvalidOperation_BadTypeAttributesNotAbstract" xml:space="preserve">
     <value>Type must be declared abstract if any of its methods are abstract.</value>
   </data>
+  <data name="AmbiguousMatch_MemberInfo" xml:space="preserve">
+    <value>Ambiguous match found for '{0} {1}'</value>
+  </data>
+  <data name="InvalidOperation_BadEmptyMethodBody" xml:space="preserve">
+    <value>Method '{0}' does not have a method body.</value>
+  </data>
 </root>

src/libraries/System.Reflection.Emit/src/System/Reflection/Emit/MethodBuilderImpl.cs

@@ -24,6 +24,7 @@ internal sealed class MethodBuilderImpl : MethodBuilder
         private ILGeneratorImpl? _ilGenerator;
         private bool _initLocals;
 
+        internal bool _canBeRuntimeImpl;
         internal DllImportData? _dllImportData;
         internal List<CustomAttributeWrapper>? _customAttributes;
         internal ParameterBuilderImpl[]? _parameterBuilders;
@@ -70,6 +71,19 @@ internal MethodBuilderImpl(string name, MethodAttributes attributes, CallingConv
 
         internal ILGeneratorImpl? ILGeneratorImpl => _ilGenerator;
 
+        public new bool IsConstructor
+        {
+            get
+            {
+                if ((_attributes & (MethodAttributes.RTSpecialName | MethodAttributes.SpecialName)) != (MethodAttributes.RTSpecialName | MethodAttributes.SpecialName))
+                {
+                    return false;
+                }
+
+                return _name.Equals(ConstructorInfo.ConstructorName) || _name.Equals(ConstructorInfo.TypeConstructorName);
+            }
+        }
+
         internal BlobBuilder GetMethodSignatureBlob() => MetadataSignatureHelper.MethodSignatureEncoder(_module,
             _parameterTypes, ReturnType, GetSignatureConvention(_callingConventions, _dllImportData), GetGenericArguments().Length, !IsStatic);
 
@@ -172,11 +186,13 @@ protected override void SetCustomAttributeCore(ConstructorInfo con, ReadOnlySpan
                 case "System.Runtime.CompilerServices.MethodImplAttribute":
                     int implValue = BinaryPrimitives.ReadUInt16LittleEndian(binaryAttribute.Slice(2));
                     _methodImplFlags |= (MethodImplAttributes)implValue;
+                    _canBeRuntimeImpl = true;
                     return;
                 case "System.Runtime.InteropServices.DllImportAttribute":
                     {
                         _dllImportData = DllImportData.CreateDllImportData(CustomAttributeInfo.DecodeCustomAttribute(con, binaryAttribute), out var preserveSig);
                         _attributes |= MethodAttributes.PinvokeImpl;
+                        _canBeRuntimeImpl = true;
                         if (preserveSig)
                         {
                             _methodImplFlags |= MethodImplAttributes.PreserveSig;
@@ -201,6 +217,8 @@ protected override void SetCustomAttributeCore(ConstructorInfo con, ReadOnlySpan
         protected override void SetImplementationFlagsCore(MethodImplAttributes attributes)
         {
             _declaringType.ThrowIfCreated();
+
+            _canBeRuntimeImpl = true;
             _methodImplFlags = attributes;
         }
 

src/libraries/System.Reflection.Emit/src/System/Reflection/Emit/ModuleBuilderImpl.cs

@@ -21,6 +21,7 @@ internal sealed class ModuleBuilderImpl : ModuleBuilder
         private readonly Dictionary<MemberInfo, EntityHandle> _memberReferences = new();
         private readonly List<TypeBuilderImpl> _typeDefinitions = new();
         private readonly Dictionary<ConstructorInfo, MemberReferenceHandle> _ctorReferences = new();
+        private readonly Guid _moduleVersionId;
         private Dictionary<string, ModuleReferenceHandle>? _moduleReferences;
         private List<CustomAttributeWrapper>? _customAttributes;
         private int _nextTypeDefRowId = 1;
@@ -40,6 +41,7 @@ internal ModuleBuilderImpl(string name, Assembly coreAssembly, MetadataBuilder b
             _name = name;
             _metadataBuilder = builder;
             _assemblyBuilder = assemblyBuilder;
+            _moduleVersionId = Guid.NewGuid();
         }
 
         [UnconditionalSuppressMessage("ReflectionAnalysis", "IL2026:RequiresUnreferencedCode", Justification = "Types are preserved via s_coreTypes")]
@@ -109,7 +111,7 @@ internal void AppendMetadata(MethodBodyStreamEncoder methodBodyEncoder)
             ModuleDefinitionHandle moduleHandle = _metadataBuilder.AddModule(
                 generation: 0,
                 moduleName: _metadataBuilder.GetOrAddString(_name),
-                mvid: _metadataBuilder.GetOrAddGuid(Guid.NewGuid()),
+                mvid: _metadataBuilder.GetOrAddGuid(_moduleVersionId),
                 encId: default,
                 encBaseId: default);
 
@@ -195,9 +197,10 @@ private void WriteInterfaceImplementations(TypeBuilderImpl typeBuilder, TypeDefi
                 }
             }
 
-            if (typeBuilder._interfaceMappings != null)
+            // Even there were no interfaces implemented it could have an override for base type abstract method
+            if (typeBuilder._methodOverrides != null)
             {
-                foreach (List<(MethodInfo ifaceMethod, MethodInfo targetMethod)> mapList in typeBuilder._interfaceMappings.Values)
+                foreach (List<(MethodInfo ifaceMethod, MethodInfo targetMethod)> mapList in typeBuilder._methodOverrides.Values)
                 {
                     foreach ((MethodInfo ifaceMethod, MethodInfo targetMethod) pair in mapList)
                     {
@@ -566,7 +569,7 @@ private AssemblyReferenceHandle GetAssemblyReference(Assembly assembly)
             if (!_assemblyReferences.TryGetValue(assembly, out var handle))
             {
                 AssemblyName aName = assembly.GetName();
-                handle = AddAssemblyReference(aName.Name!, aName.Version, aName.CultureName, aName.GetPublicKeyToken(), aName.Flags, aName.ContentType);
+                handle = AddAssemblyReference(aName.Name, aName.Version, aName.CultureName, aName.GetPublicKeyToken(), aName.Flags, aName.ContentType);
                 _assemblyReferences.Add(assembly, handle);
             }
 
@@ -687,10 +690,10 @@ private ParameterHandle AddParameter(ParameterBuilderImpl parameter) =>
                 name: parameter.Name != null ? _metadataBuilder.GetOrAddString(parameter.Name) : default,
                 sequenceNumber: parameter.Position);
 
-        private AssemblyReferenceHandle AddAssemblyReference(string name, Version? version, string? culture,
+        private AssemblyReferenceHandle AddAssemblyReference(string? name, Version? version, string? culture,
             byte[]? publicKeyToken, AssemblyNameFlags flags, AssemblyContentType contentType) =>
             _metadataBuilder.AddAssemblyReference(
-                name: _metadataBuilder.GetOrAddString(name),
+                name: name == null ? default : _metadataBuilder.GetOrAddString(name),
                 version: version ?? new Version(0, 0, 0, 0),
                 culture: (culture == null) ? default : _metadataBuilder.GetOrAddString(value: culture),
                 publicKeyOrToken: (publicKeyToken == null) ? default : _metadataBuilder.GetOrAddBlob(publicKeyToken), // reference has token, not full public key
@@ -744,28 +747,29 @@ internal TypeBuilder DefineNestedType(string name, TypeAttributes attr, [Dynamic
         public override string Name => "<In Memory Module>";
         public override string ScopeName => _name;
         public override Assembly Assembly => _assemblyBuilder;
+        public override Guid ModuleVersionId => _moduleVersionId;
         public override bool IsDefined(Type attributeType, bool inherit) => throw new NotImplementedException();
 
         public override int GetFieldMetadataToken(FieldInfo field)
         {
-            if (field is FieldBuilderImpl fb)
+            if (field is FieldBuilderImpl fb && fb._handle != default)
             {
                 return MetadataTokens.GetToken(fb._handle);
             }
 
-            return field.MetadataToken;
+            return 0;
         }
 
         public override int GetMethodMetadataToken(ConstructorInfo constructor) => throw new NotImplementedException();
 
         public override int GetMethodMetadataToken(MethodInfo method)
         {
-            if (method is MethodBuilderImpl mb)
+            if (method is MethodBuilderImpl mb && mb._handle != default)
             {
                 return MetadataTokens.GetToken(mb._handle);
             }
 
-            return method.MetadataToken;
+            return 0;
         }
 
         public override int GetStringMetadataToken(string stringConstant) => MetadataTokens.GetToken(_metadataBuilder.GetOrAddUserString(stringConstant));