Refactor KClassValue to store ClassLiteralValue internally

Only invariant array projections and non-null element types will be
supported soon (see KT-26568), so it makes no sense to store the
complete type in KClassValue. What we need is only the ClassId of the
class, and the number of times it's wrapped into kotlin/Array, which is
exactly what ClassLiteralValue represents.

This change helps in decoupling annotation values from
descriptors/types. The only constant value that depends on descriptors
is now AnnotationValue.

 #KT-26582 Fixed

compiler/serialization/src/org/jetbrains/kotlin/serialization/AnnotationSerializer.kt

@@ -16,8 +16,6 @@
 
 package org.jetbrains.kotlin.serialization
 
-import org.jetbrains.kotlin.builtins.KotlinBuiltIns
-import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationArgumentVisitor
 import org.jetbrains.kotlin.descriptors.annotations.AnnotationDescriptor
 import org.jetbrains.kotlin.metadata.ProtoBuf
@@ -100,22 +98,11 @@ class AnnotationSerializer(private val stringTable: DescriptorAwareStringTable)
             }
 
             override fun visitKClassValue(value: KClassValue, data: Unit) {
-                var kotlinType = value.value
-                var arrayDimensions = 0
-                while (KotlinBuiltIns.isArray(kotlinType)) {
-                    // We only support invariant projections and non-null array element types, see KT-26568
-                    kotlinType = kotlinType.arguments.single().type
-                    arrayDimensions++
-                }
-
-                val descriptor = kotlinType.constructor.declarationDescriptor as? ClassDescriptor
-                    ?: throw UnsupportedOperationException("Class literal annotation argument should be a class: $value")
-
                 type = Type.CLASS
-                classId = stringTable.getFqNameIndex(descriptor)
+                classId = stringTable.getQualifiedClassNameIndex(value.classId)
 
-                if (arrayDimensions > 0) {
-                    arrayDimensionCount = arrayDimensions
+                if (value.arrayDimensions > 0) {
+                    arrayDimensionCount = value.arrayDimensions
                 }
             }