[kotlin] Add a small KDoc to getAllSuperClassifiers function

core/descriptors/src/org/jetbrains/kotlin/resolve/DescriptorUtils.kt

@@ -370,6 +370,10 @@ val DeclarationDescriptor.isExtensionProperty: Boolean
 fun ClassDescriptor.getAllSuperclassesWithoutAny() =
     generateSequence(getSuperClassNotAny(), ClassDescriptor::getSuperClassNotAny).toCollection(SmartList<ClassDescriptor>())
 
+/**
+ * Returns a sequence of all super classifiers (both classes and interfaces) for [this] classifier,
+ * including [this] classifier itself.
+ */
 fun ClassifierDescriptor.getAllSuperClassifiers(): Sequence<ClassifierDescriptor> {
     val set = hashSetOf<ClassifierDescriptor>()