When generating enums with auto insertion location = false, don't attempt to sort the members.

MAS should always disable auto insertion location.

src/Features/Core/Portable/MetadataAsSource/AbstractMetadataAsSourceService.cs

@@ -100,7 +100,7 @@ private static CodeGenerationOptions CreateCodeGenerationOptions(Location contex
                 generateMethodBodies: false,
                 generateDocumentationComments: true,
                 mergeAttributes: false,
-                autoInsertionLocation: !((symbol is ITypeSymbol) && (symbol as ITypeSymbol).IsEnumType()));
+                autoInsertionLocation: false);
         }
     }
 }

src/Workspaces/Core/Portable/CodeGeneration/AbstractCodeGenerationService.cs

@@ -262,7 +262,10 @@ protected static T Cast<T>(object value)
                 // Metadata as source generates complete declarations and doesn't modify
                 // existing ones. We can take the members to generate, sort them once,
                 // and then add them in that order to the end of the destination.
-                newMembers.Sort(GetMemberComparer());
+                if (!GeneratingEnum(members))
+                {
+                    newMembers.Sort(GetMemberComparer());
+                }
 
                 currentDestination = this.AddMembers(currentDestination, newMembers);
             }
@@ -270,6 +273,13 @@ protected static T Cast<T>(object value)
             return currentDestination;
         }
 
+        private bool GeneratingEnum(IEnumerable<ISymbol> members)
+        {
+            // If we're generating an enum, every member will be an enum field
+            var field = members.FirstOrDefault() as IFieldSymbol;
+            return field != null && field.ContainingType.IsEnumType();
+        }
+
         protected abstract IComparer<SyntaxNode> GetMemberComparer();
 
         protected static CodeGenerationOptions CreateOptionsForMultipleMembers(CodeGenerationOptions options)