Expect/actual support in klibs under -Xklib-mpp

compiler/frontend/src/org/jetbrains/kotlin/config/AnalysisFlags.kt

@@ -12,6 +12,9 @@ object AnalysisFlags {
     @JvmStatic
     val multiPlatformDoNotCheckActual by AnalysisFlag.Delegates.Boolean
 
+    @JvmStatic
+    val klibBasedMpp by AnalysisFlag.Delegates.Boolean
+
     @JvmStatic
     val experimental by AnalysisFlag.Delegates.ListOfStrings
 

compiler/frontend/src/org/jetbrains/kotlin/config/CommonConfigurationKeys.kt

@@ -44,6 +44,9 @@ object CommonConfigurationKeys {
 
     @JvmField
     val USE_FIR = CompilerConfigurationKey.create<Boolean>("front-end IR")
+
+    @JvmField
+    val KLIB_MPP = CompilerConfigurationKey.create<Boolean>("Klib based MPP")
 }
 
 var CompilerConfiguration.languageVersionSettings: LanguageVersionSettings

compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ExpectedActualDeclarationChecker.kt

@@ -54,6 +54,8 @@ class ExpectedActualDeclarationChecker(
 
     override fun check(declaration: KtDeclaration, descriptor: DeclarationDescriptor, context: DeclarationCheckerContext) {
         if (!context.languageVersionSettings.supportsFeature(LanguageFeature.MultiPlatformProjects)) return
+        // TODO: we need a klib based MPP aware ModuleStructureOracle. Just disable the checks for now.
+        if (context.languageVersionSettings.getFlag(AnalysisFlags.klibBasedMpp)) return
 
         // Note that this check is necessary, because for default accessors KtProperty is passed for KtDeclaration, so this
         // case won't be covered by the next check (also, it accidentally fixes KT-28385)