[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/tree/src/org/jetbrains/kotlin/fir/declarations/ExpectActualAttributes.kt

@@ -8,8 +8,10 @@ package org.jetbrains.kotlin.fir.declarations
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.symbols.FirBasedSymbol
 import org.jetbrains.kotlin.fir.symbols.SymbolInternals
+import org.jetbrains.kotlin.fir.symbols.impl.FirFunctionSymbol
 import org.jetbrains.kotlin.fir.symbols.lazyResolveToPhase
 import org.jetbrains.kotlin.resolve.multiplatform.ExpectActualCompatibility
+import org.jetbrains.kotlin.resolve.multiplatform.compatible
 import java.util.*
 
 private object ExpectForActualAttributeKey : FirDeclarationDataKey()
@@ -21,6 +23,24 @@ typealias ExpectForActualData = Map<ExpectActualCompatibility<FirBasedSymbol<*>>
 var FirDeclaration.expectForActual: ExpectForActualData? by FirDeclarationDataRegistry.data(ExpectForActualAttributeKey)
 private var FirDeclaration.actualForExpectMap: WeakHashMap<FirSession, FirBasedSymbol<*>>? by FirDeclarationDataRegistry.data(ActualForExpectAttributeKey)
 
+fun FirFunctionSymbol<*>.getSingleCompatibleExpectForActualOrNull() =
+    (this as FirBasedSymbol<*>).getSingleCompatibleExpectForActualOrNull() as? FirFunctionSymbol<*>
+
+fun FirBasedSymbol<*>.getSingleCompatibleExpectForActualOrNull(): FirBasedSymbol<*>? {
+    val expectForActual = expectForActual ?: return null
+    var compatibleActuals: List<FirBasedSymbol<*>>? = null
+    for ((key, item) in expectForActual) {
+        if (key.compatible) {
+            if (compatibleActuals == null) {
+                compatibleActuals = item
+            } else {
+                return null // Exit if there are more than one list with compatible actuals
+            }
+        }
+    }
+    return compatibleActuals?.singleOrNull()
+}
+
 val FirBasedSymbol<*>.expectForActual: ExpectForActualData?
     get() {
         lazyResolveToPhase(FirResolvePhase.EXPECT_ACTUAL_MATCHING)

compiler/fir/tree/src/org/jetbrains/kotlin/fir/declarations/FirResolvePhase.kt

@@ -14,11 +14,11 @@ enum class FirResolvePhase(val noProcessor: Boolean = false) {
     SEALED_CLASS_INHERITORS,
     TYPES,
     STATUS,
+    EXPECT_ACTUAL_MATCHING,
     ARGUMENTS_OF_ANNOTATIONS,
     CONTRACTS,
     IMPLICIT_TYPES_BODY_RESOLVE,
     ANNOTATIONS_ARGUMENTS_MAPPING,
-    EXPECT_ACTUAL_MATCHING,
     BODY_RESOLVE;
 
     val requiredToLaunch: FirResolvePhase