Add more runtime, avoid codegen for interfaces. (#47)

* Add more runtime, avoid codegen for interfaces.

* backend: fix bug in RTTIGenerator

kotlin.Nothing has no supertypes

* runtime: enable kotlin.Nothing

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IrToBitcode.kt

@@ -2,6 +2,7 @@ package org.jetbrains.kotlin.backend.konan.llvm
 
 import kotlin_native.interop.*
 import llvm.*
+import org.jetbrains.kotlin.backend.konan.isInterface
 import org.jetbrains.kotlin.backend.konan.isIntrinsic
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.descriptors.*
@@ -204,6 +205,11 @@ internal class CodeGeneratorVisitor(val context: Context) : IrElementVisitorVoid
             return
         }
 
+        if (declaration.descriptor.isInterface) {
+            // Do not generate any code for interfaces.
+            return
+        }
+
         super.visitClass(declaration)
     }
 

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/RTTIGenerator.kt

@@ -81,7 +81,7 @@ internal class RTTIGenerator(override val context: Context) : ContextUtils {
             return emptyList()
         }
 
-        val superVtableEntries = if (KotlinBuiltIns.isAny(classDesc)) {
+        val superVtableEntries = if (KotlinBuiltIns.isSpecialClassWithNoSupertypes(classDesc)) {
             emptyList()
         } else {
             getVtableEntries(classDesc.getSuperClassOrAny())