[class-parse] Add Kotlin metadata to -dump.

tools/class-parse/Program.cs

@@ -8,6 +8,8 @@
 using Mono.Options;
 
 using Xamarin.Android.Tools.Bytecode;
+using System.Text.Json;
+using System.Text.Json.Serialization;
 
 namespace Xamarin.Android.Tools {
 
@@ -159,6 +161,32 @@ static void DumpClassFile (ClassFile c, TextWriter output)
 					output.WriteLine ("\t\t{0}", attr);
 				}
 			}
+
+			// Output Kotlin metadata if it exists
+			var kotlin_metadata = c.Attributes.OfType<RuntimeVisibleAnnotationsAttribute> ()
+				.FirstOrDefault ()?.Annotations
+				.FirstOrDefault (a => a.Type == "Lkotlin/Metadata;");
+
+			if (kotlin_metadata is not null) {
+				var meta = KotlinMetadata.FromAnnotation (kotlin_metadata);
+				var jopt = new JsonSerializerOptions {
+					ReferenceHandler    = ReferenceHandler.Preserve,
+					WriteIndented       = true,
+				};
+
+				if (meta.AsClassMetadata () is KotlinClass kc) {
+					output.WriteLine ();
+					var json = JsonSerializer.Serialize (kc, jopt);
+					output.WriteLine ($"Kotlin Class Metadata [{meta.MetadataVersion}]: {json}");
+				} else if (meta.AsFileMetadata () is KotlinFile kf) {
+					output.WriteLine ();
+					var json = JsonSerializer.Serialize (kf, jopt);
+					output.WriteLine ($"Kotlin File Metadata [{meta.MetadataVersion}]: {json}");
+				}
+
+				output.WriteLine ();
+				output.WriteLine ($"Kotlin Metadata String Table: {JsonSerializer.Serialize (meta.Data2, jopt)}");
+			}
 		}
 	}
 }