[K/N] Consolidate forward declarations handling

This is refactoring in preparation for KT-59764.
Names and layout of forward declarations related classes
was copy-pasted many times over compiler code.

Implementing KT-59764 would require copy-pasting it two more times.
So instead of doing this it was put in single place.

No behaviour changes intended in this commit.

kotlin-native/backend.native/build.gradle

@@ -157,6 +157,7 @@ dependencies {
     compilerImplementation project(":kotlin-compiler")
     compilerApi project(":native:kotlin-native-utils")
     compilerApi project(":core:descriptors")
+    compilerApi project(":core:compiler.common.native")
     compilerApi project(":compiler:ir.tree")
     compilerApi project(":compiler:ir.backend.common")
     compilerApi project(":compiler:util")

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/Fir2Ir.kt

@@ -35,8 +35,8 @@ import org.jetbrains.kotlin.ir.types.IrTypeSystemContextImpl
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.ir.visitors.acceptVoid
 import org.jetbrains.kotlin.library.metadata.KlibMetadataFactories
-import org.jetbrains.kotlin.library.metadata.impl.ForwardDeclarationKind
 import org.jetbrains.kotlin.storage.LockBasedStorageManager
+import org.jetbrains.kotlin.name.*
 
 internal val KlibFactories = KlibMetadataFactories(::KonanBuiltIns, DynamicTypeDeserializer, PlatformDependentTypeTransformer.None)
 
@@ -111,7 +111,7 @@ internal fun PhaseContext.fir2Ir(
         }
         // This packages exists in all platform libraries, but can contain only synthetic declarations.
         // These declarations are not really located in klib, so we don't need to depend on klib to use them.
-        removeAll(ForwardDeclarationKind.values().map { it.packageFqName })
+        removeAll(NativeForwardDeclarationKind.entries.map { it.packageFqName })
     }.toList()
 
 

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/ObjCInterop.kt

@@ -17,6 +17,7 @@ import org.jetbrains.kotlin.ir.descriptors.IrBasedClassConstructorDescriptor
 import org.jetbrains.kotlin.ir.expressions.IrConstructorCall
 import org.jetbrains.kotlin.ir.types.classOrNull
 import org.jetbrains.kotlin.ir.util.*
+import org.jetbrains.kotlin.name.NativeForwardDeclarationKind
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.ExternalOverridabilityCondition
@@ -37,7 +38,6 @@ internal val objCDirectFqName = interopPackageName.child(Name.identifier("ObjCDi
 internal val objCMethodFqName = interopPackageName.child(Name.identifier("ObjCMethod"))
 internal val objCConstructorFqName = FqName("kotlinx.cinterop.ObjCConstructor")
 internal val objCFactoryFqName = interopPackageName.child(Name.identifier("ObjCFactory"))
-private val objcnamesForwardDeclarationsPackageName = Name.identifier("objcnames")
 
 fun ClassDescriptor.isObjCClass(): Boolean =
                 this.containingDeclaration.fqNameSafe != interopPackageName &&
@@ -64,8 +64,10 @@ fun IrClass.isExternalObjCClass(): Boolean = this.isObjCClass() &&
             it.annotations.hasAnnotation(externalObjCClassFqName)
         }
 
-fun ClassDescriptor.isObjCForwardDeclaration(): Boolean =
-        this.findPackage().fqName.startsWith(objcnamesForwardDeclarationsPackageName)
+fun ClassDescriptor.isObjCForwardDeclaration(): Boolean = when (NativeForwardDeclarationKind.packageFqNameToKind[findPackage().fqName]) {
+    null, NativeForwardDeclarationKind.Struct -> false
+    NativeForwardDeclarationKind.ObjCProtocol, NativeForwardDeclarationKind.ObjCClass -> true
+}
 
 fun IrClass.isObjCForwardDeclaration(): Boolean =
         getPackageFragment().packageFqName.startsWith(objcnamesForwardDeclarationsPackageName)

kotlin-native/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/serialization/KonanIrlinker.kt

@@ -33,7 +33,6 @@ import org.jetbrains.kotlin.backend.konan.descriptors.isFromInteropLibrary
 import org.jetbrains.kotlin.backend.konan.descriptors.isInteropLibrary
 import org.jetbrains.kotlin.backend.konan.ir.interop.IrProviderForCEnumAndCStructStubs
 import org.jetbrains.kotlin.backend.konan.ir.konanLibrary
-import org.jetbrains.kotlin.backend.konan.ir.isFromInteropLibrary
 import org.jetbrains.kotlin.backend.konan.ir.isFromInteropLibraryByDescriptor
 import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.descriptors.konan.isNativeStdlib
@@ -58,6 +57,7 @@ import org.jetbrains.kotlin.library.KotlinLibrary
 import org.jetbrains.kotlin.library.metadata.DeserializedKlibModuleOrigin
 import org.jetbrains.kotlin.library.metadata.klibModuleOrigin
 import org.jetbrains.kotlin.name.ClassId
+import org.jetbrains.kotlin.name.NativeForwardDeclarationKind
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.descriptorUtil.module
@@ -472,12 +472,7 @@ internal class KonanIrLinker(
 ) : KotlinIrLinker(currentModule, messageLogger, builtIns, symbolTable, exportedDependencies) {
 
     companion object {
-        private val C_NAMES_NAME = Name.identifier("cnames")
-        private val OBJC_NAMES_NAME = Name.identifier("objcnames")
-
         val FORWARD_DECLARATION_ORIGIN = object : IrDeclarationOriginImpl("FORWARD_DECLARATION_ORIGIN") {}
-
-        const val offset = SYNTHETIC_OFFSET
     }
 
     override fun isBuiltInModule(moduleDescriptor: ModuleDescriptor): Boolean = moduleDescriptor.isNativeStdlib()
@@ -1111,9 +1106,7 @@ internal class KonanIrLinker(
 
         private fun IdSignature.isForwardDeclarationSignature(): Boolean {
             if (isPubliclyVisible) {
-                return packageFqName().run {
-                    startsWith(C_NAMES_NAME) || startsWith(OBJC_NAMES_NAME)
-                }
+                return packageFqName() in NativeForwardDeclarationKind.packageFqNameToKind
             }
 
             return false