Fix NPE from KotlinBuiltInDecompiler

This happened because of bae955a: similarly to the corresponding code in
the compiler, the IDE should also skip the metadata for kotlin.Cloneable when
decompiling built-ins because the deserializer is not going to resolve this
class from the metadata

(cherry picked from commit cdeabf2)

Author: udalov

idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/builtIns/KotlinBuiltInDecompiler.kt

@@ -36,6 +36,7 @@ import org.jetbrains.kotlin.renderer.DescriptorRenderer
 import org.jetbrains.kotlin.serialization.builtins.BuiltInsProtoBuf
 import org.jetbrains.kotlin.serialization.deserialization.MetadataPackageFragment
 import org.jetbrains.kotlin.serialization.deserialization.NameResolverImpl
+import org.jetbrains.kotlin.utils.addIfNotNull
 import java.io.ByteArrayInputStream
 
 class KotlinBuiltInDecompiler : ClassFileDecompilers.Full() {
@@ -82,7 +83,7 @@ fun buildDecompiledTextForBuiltIns(builtInFile: VirtualFile): DecompiledText {
             declarations.addAll(resolver.resolveDeclarationsInFacade(packageFqName))
             for (classProto in file.classesToDecompile) {
                 val classId = file.nameResolver.getClassId(classProto.fqName)
-                declarations.add(resolver.resolveTopLevelClass(classId)!!)
+                declarations.addIfNotNull(resolver.resolveTopLevelClass(classId))
             }
             return buildDecompiledText(packageFqName, declarations, decompilerRendererForBuiltIns)
         }

idea/idea-analysis/src/org/jetbrains/kotlin/idea/decompiler/js/KotlinJavaScriptMetaFileDecompiler.kt

@@ -33,6 +33,7 @@ import org.jetbrains.kotlin.serialization.deserialization.NameResolverImpl
 import org.jetbrains.kotlin.serialization.js.JsProtoBuf
 import org.jetbrains.kotlin.serialization.js.JsSerializerProtocol
 import org.jetbrains.kotlin.utils.JsMetadataVersion
+import org.jetbrains.kotlin.utils.addIfNotNull
 import java.io.ByteArrayInputStream
 import java.io.IOException
 
@@ -76,7 +77,7 @@ fun buildDecompiledTextFromJsMetadata(kjsmFile: VirtualFile): DecompiledText {
             declarations.addAll(resolver.resolveDeclarationsInFacade(packageFqName))
             for (klass in file.classesToDecompile) {
                 val classId = file.nameResolver.getClassId(klass.fqName)
-                declarations.add(resolver.resolveTopLevelClass(classId)!!)
+                declarations.addIfNotNull(resolver.resolveTopLevelClass(classId))
             }
             return buildDecompiledText(packageFqName, declarations, decompilerRendererForJS)
         }