[Commonizer] Metadata comparator: Fully support contracts comparison

^KT-62753

native/commonizer/src/org/jetbrains/kotlin/commonizer/metadata/utils/MetadataDeclarationsComparator.kt

@@ -54,6 +54,7 @@ class MetadataDeclarationsComparator private constructor(private val config: Con
     }
 
     @Suppress("MemberVisibilityCanBePrivate", "unused")
+    @OptIn(ExperimentalContracts::class)
     sealed interface PathElement {
         val name: String
 
@@ -109,9 +110,20 @@ class MetadataDeclarationsComparator private constructor(private val config: Con
             override val name get() = entryA.name
         }
 
+        class Contract(val contractA: KmContract, val contractB: KmContract) : PathElement {
+            override val name get() = "contract"
+        }
+
+        class Effect(val effectA: KmEffect, val effectB: KmEffect, val index: Int) : PathElement {
+            override val name get() = index.toString()
+        }
+
+        class EffectExpression(val effectExpressionA: KmEffectExpression, val effectExpressionB: KmEffectExpression, val index: Int) : PathElement {
+            override val name get() = index.toString()
+        }
+
         companion object {
-            internal fun <E : Any> guess(entityA: E, entityB: E, entityKind: EntityKind, entityKey: String?): PathElement {
+            internal fun <E : Any> guess(entityA: E, entityB: E, entityKind: EntityKind, entityKey: String?): PathElement = when {
-                return when {
                 entityA is KmClass && entityB is KmClass -> Class(entityA, entityB)
                 entityA is KmTypeAlias && entityB is KmTypeAlias -> TypeAlias(entityA, entityB)
                 entityA is KmProperty && entityB is KmProperty -> Property(entityA, entityB)
@@ -135,12 +147,20 @@ class MetadataDeclarationsComparator private constructor(private val config: Con
                     val index = entityKey!!.toInt()
                     TypeArgument(entityA, entityB, index)
                 }
+                entityA is KmContract && entityB is KmContract -> Contract(entityA, entityB)
+                entityA is KmEffect && entityB is KmEffect -> {
+                    val index = entityKey!!.toInt()
+                    Effect(entityA, entityB, index)
+                }
+                entityA is KmEffectExpression && entityB is KmEffectExpression -> {
+                    val index = entityKey!!.toInt()
+                    EffectExpression(entityA, entityB, index)
+                }
                 entityA is KlibEnumEntry && entityB is KlibEnumEntry -> EnumEntry(entityA, entityB)
                 else -> error("Unknown combination of entities: ${entityA::class.java}, ${entityB::class.java}")
             }
         }
     }
-    }
 
     sealed interface EntityKind {
         enum class AnnotationKind : EntityKind {