[Interop][Linker] Mark interop declarations

Add IS_NATIVE_INTEROP_LIBRARY flag to IdSignature of interop declarations.
It allows to link metadata-based interop libraries.

Note that libraries that depend on metadata-based interop libraries are not supported yet.

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

@@ -1,8 +1,62 @@
 package org.jetbrains.kotlin.backend.konan.serialization
 
 import org.jetbrains.kotlin.backend.common.serialization.signature.IdSignatureDescriptor
+import org.jetbrains.kotlin.backend.konan.descriptors.isFromInteropLibrary
+import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.ir.util.IdSignature
 import org.jetbrains.kotlin.ir.util.KotlinMangler
+import org.jetbrains.kotlin.resolve.descriptorUtil.module
 
-class KonanIdSignaturer(mangler: KotlinMangler.DescriptorMangler) : IdSignatureDescriptor(mangler) {
+class KonanIdSignaturer(private val mangler: KotlinMangler.DescriptorMangler) : IdSignatureDescriptor(mangler) {
 
+    override fun createSignatureBuilder(): DescriptorBasedSignatureBuilder =
+            KonanDescriptorBasedSignatureBuilder(mangler)
+
+    private class KonanDescriptorBasedSignatureBuilder(
+            mangler: KotlinMangler.DescriptorMangler
+    ) : DescriptorBasedSignatureBuilder(mangler) {
+
+        /**
+         * We need a way to distinguish interop declarations from usual ones
+         * to be able to link against them. We do it by marking them with
+         * [IdSignature.Flags.IS_NATIVE_INTEROP_LIBRARY] flag.
+         */
+        private fun markInteropDeclaration(descriptor: DeclarationDescriptor) {
+            if (descriptor.module.isFromInteropLibrary()) {
+                mask = mask or IdSignature.Flags.IS_NATIVE_INTEROP_LIBRARY.encode(true)
+            }
+        }
+
+        override fun platformSpecificAlias(descriptor: TypeAliasDescriptor) {
+            markInteropDeclaration(descriptor)
+        }
+
+        override fun platformSpecificClass(descriptor: ClassDescriptor) {
+            markInteropDeclaration(descriptor)
+        }
+
+        override fun platformSpecificConstructor(descriptor: ConstructorDescriptor) {
+            markInteropDeclaration(descriptor)
+        }
+
+        override fun platformSpecificFunction(descriptor: FunctionDescriptor) {
+            markInteropDeclaration(descriptor)
+        }
+
+        override fun platformSpecificGetter(descriptor: PropertyGetterDescriptor) {
+            markInteropDeclaration(descriptor)
+        }
+
+        override fun platformSpecificPackage(descriptor: PackageFragmentDescriptor) {
+            markInteropDeclaration(descriptor)
+        }
+
+        override fun platformSpecificProperty(descriptor: PropertyDescriptor) {
+            markInteropDeclaration(descriptor)
+        }
+
+        override fun platformSpecificSetter(descriptor: PropertySetterDescriptor) {
+            markInteropDeclaration(descriptor)
+        }
+    }
 }