Revert 2 fixes that build for .NET framework

Author: buyaa-n

src/libraries/Common/src/System/Resources/ResourceWriter.cs

@@ -488,7 +488,11 @@ private static ResourceTypeCode FindTypeCode(object? value, List<string> types)
                 if (typeName.StartsWith("ResourceTypeCode.", StringComparison.Ordinal))
                 {
                     typeName = typeName.Substring(17);  // Remove through '.'
+#if NETCOREAPP
                     ResourceTypeCode typeCode = Enum.Parse<ResourceTypeCode>(typeName);
+#else
+                    ResourceTypeCode typeCode = (ResourceTypeCode)Enum.Parse(typeof(ResourceTypeCode), typeName);
+#endif
                     return typeCode;
                 }
             }

src/libraries/System.Text.Encodings.Web/src/System/Text/Encodings/Web/ThrowHelper.cs

@@ -22,7 +22,7 @@ internal static void ThrowArgumentOutOfRangeException(ExceptionArgument argument
 
         private static string GetArgumentName(ExceptionArgument argument)
         {
-            Debug.Assert(Enum.IsDefined(argument),
+            Debug.Assert(Enum.IsDefined(typeof(ExceptionArgument), argument),
                 "The enum value is not defined, please check the ExceptionArgument Enum.");
 
             return argument.ToString();

src/tasks/AotCompilerTask/MonoAOTCompiler.cs

@@ -373,7 +373,7 @@ private bool ProcessAndValidateArguments()
 
         if (!Enum.TryParse(Mode, true, out parsedAotMode))
         {
-            Log.LogError($"Unknown Mode value: {Mode}. '{nameof(Mode)}' must be one of: {string.Join(",", Enum.GetNames<MonoAotMode>())}");
+            Log.LogError($"Unknown Mode value: {Mode}. '{nameof(Mode)}' must be one of: {string.Join(",", Enum.GetNames(typeof(MonoAotMode)))}");
             return false;
         }
 

src/tasks/Microsoft.NET.WebAssembly.Webcil/WasmModuleReader.cs

@@ -101,7 +101,7 @@ private bool DoVisitSection(out bool shouldStop)
         shouldStop = false;
         byte code = _reader.ReadByte();
         Section section = (Section)code;
-        if (!Enum.IsDefined(section))
+        if (!Enum.IsDefined(typeof(Section), section))
             return false;
         uint sectionSize = ReadULEB128();
 

src/tasks/WasmAppBuilder/EmccCompile.cs

@@ -75,7 +75,7 @@ private bool ExecuteActual()
 
             if (!Enum.TryParse(OutputMessageImportance, ignoreCase: true, out MessageImportance messageImportance))
             {
-                Log.LogError($"Invalid value for OutputMessageImportance={OutputMessageImportance}. Valid values: {string.Join(", ", Enum.GetNames<MessageImportance>())}");
+                Log.LogError($"Invalid value for OutputMessageImportance={OutputMessageImportance}. Valid values: {string.Join(", ", Enum.GetNames(typeof(MessageImportance)))}");
                 return false;
             }