Kapt: Add Kotlin location to diagnostics reported in Kapt stubs

plugins/kapt3/kapt3-compiler/testData/converter/invalidFieldName.txt

@@ -1,8 +1,10 @@
 @kotlin.Metadata()
 @java.lang.annotation.Retention(value = java.lang.annotation.RetentionPolicy.RUNTIME)
 @Anno(color = Color.InvalidFieldName)
+@kapt.internal.KaptMetadata()
 public abstract @interface Anno {
 
+    @kapt.internal.KaptSignature(value = "color()LColor;")
     public abstract Color color();
 }
 
@@ -10,9 +12,29 @@ public abstract @interface Anno {
 
 
 @kotlin.Metadata()
+@kapt.internal.KaptMetadata()
 public enum Color {
-    /*public static final*/ BLACK /* = new BLACK() */;
+    /*public static final*/ BLACK /* = new Color() */;
 
+    @kapt.internal.KaptSignature(value = "<init>(Ljava/lang/String;I)V")
     Color() {
     }
 }
+
+////////////////////
+
+package kapt.internal;
+
+public @interface KaptMetadata {
+
+    public java.lang.String value();
+}
+
+////////////////////
+
+package kapt.internal;
+
+public @interface KaptSignature {
+
+    public java.lang.String value();
+}