Drop synthetic class kind Function, drop Metadata#xi

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/JvmAnnotationNames.java

@@ -44,7 +44,6 @@ public final class JvmAnnotationNames {
     public static final String KIND_FIELD_NAME = "k";
     public static final String METADATA_DATA_FIELD_NAME = "d1";
     public static final String METADATA_STRINGS_FIELD_NAME = "d2";
-    public static final String SYNTHETIC_CLASS_KIND_FIELD_NAME = "xi";
     public static final String METADATA_MULTIFILE_CLASS_NAME_FIELD_NAME = "xs";
     public static final String DATA_FIELD_NAME = "data";
     public static final String STRINGS_FIELD_NAME = "strings";

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/header/KotlinClassHeader.kt

@@ -44,9 +44,5 @@ class KotlinClassHeader(
         }
     }
 
-    enum class SyntheticClassKind(val id: Int) {
-        FUNCTION(1),
-    }
-
     override fun toString() = "$kind version=$metadataVersion"
 }