[K2] Enable tests for metadata for nested types.

compiler/fir/fir-serialization/src/org/jetbrains/kotlin/fir/serialization/FirElementSerializer.kt

@@ -32,7 +32,6 @@ import org.jetbrains.kotlin.fir.resolve.providers.symbolProvider
 import org.jetbrains.kotlin.fir.scopes.*
 import org.jetbrains.kotlin.fir.scopes.impl.nestedClassifierScope
 import org.jetbrains.kotlin.fir.serialization.constant.*
-import org.jetbrains.kotlin.fir.serialization.constant.toConstantValue
 import org.jetbrains.kotlin.fir.symbols.impl.*
 import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.fir.types.builder.buildResolvedTypeRef

libraries/tools/kotlinp/testData/EnumEntries.kt

@@ -1,4 +1,3 @@
-// IGNORE K2
 // !LANGUAGE: +EnumEntries
 
 enum class MyEnum {

libraries/tools/kotlinp/testData/NestedClasses.kt

@@ -1,5 +1,3 @@
-// IGNORE K2
-
 interface A {
     interface B {
         interface C