Kotlin: Don't warn if we can't find a label for a fake owner

The fake owner probably just wasn't extracted

Author: igfoo

java/kotlin-extractor/src/main/kotlin/KotlinFileExtractor.kt

@@ -205,7 +205,7 @@ open class KotlinFileExtractor(
     }
 
     @OptIn(ObsoleteDescriptorBasedAPI::class)
-    private fun isFake(d: IrDeclarationWithVisibility): Boolean {
+    fun isFake(d: IrDeclarationWithVisibility): Boolean {
         val hasFakeVisibility =
             d.visibility.let {
                 it is DelegatedDescriptorVisibility && it.delegate == Visibilities.InvisibleFake

java/kotlin-extractor/src/main/kotlin/comments/CommentExtractor.kt

@@ -41,7 +41,13 @@ open class CommentExtractor(
                 tw.getExistingLabelFor<DbTop>(label)
             }
         if (existingLabel == null) {
-            logger.warn("Couldn't get existing label for $label")
+            // Sometimes we don't extract elements.
+            // The actual extractor logic is a bit more nuanced than
+            // just "isFake", but just checking isFake is good enough
+            // to not bother with a warning.
+            if(element !is IrDeclarationWithVisibility || !fileExtractor.isFake(element)) {
+                logger.warn("Couldn't get existing label for $label")
+            }
             return null
         }
         return existingLabel