[FIR & IR] Support of default values for arguments in expect functions

Add FirActualDeclarationChecker that checks expect/actual return types

^KT-56331 Fixed, ^KT-56334 Fixed

compiler/fir/providers/src/org/jetbrains/kotlin/fir/types/ExpectActualUtils.kt

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.fir.types
+
+import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.resolve.substitution.ConeSubstitutor
+import org.jetbrains.kotlin.fir.resolve.substitution.ConeSubstitutorByMap
+import org.jetbrains.kotlin.fir.resolve.substitution.chain
+import org.jetbrains.kotlin.fir.symbols.impl.FirTypeParameterSymbol
+import org.jetbrains.kotlin.types.AbstractTypeChecker
+
+fun createExpectActualTypeParameterSubstitutor(
+    expectedTypeParameters: List<FirTypeParameterSymbol>,
+    actualTypeParameters: List<FirTypeParameterSymbol>,
+    useSiteSession: FirSession,
+    parentSubstitutor: ConeSubstitutor? = null
+): ConeSubstitutor {
+    val substitution = expectedTypeParameters.zip(actualTypeParameters).associate { (expectedParameterSymbol, actualParameterSymbol) ->
+        expectedParameterSymbol to actualParameterSymbol.toLookupTag().constructType(emptyArray(), isNullable = false)
+    }
+    val substitutor = ConeSubstitutorByMap(
+        substitution,
+        useSiteSession
+    )
+    if (parentSubstitutor == null) {
+        return substitutor
+    }
+    return substitutor.chain(parentSubstitutor)
+}
+
+fun areCompatibleExpectActualTypes(
+    expectedType: ConeKotlinType?,
+    actualType: ConeKotlinType?,
+    actualSession: FirSession
+): Boolean {
+    if (expectedType == null) return actualType == null
+    if (actualType == null) return false
+
+    return AbstractTypeChecker.equalTypes(
+        actualSession.typeContext,
+        expectedType,
+        actualType
+    )
+}