Fix Klib file check.

#KT-37876

idea/idea-analysis/src/org/jetbrains/kotlin/idea/klib/utils.kt

@@ -5,6 +5,8 @@
 
 package org.jetbrains.kotlin.idea.klib
 
+import com.intellij.ide.highlighter.ArchiveFileType
+import com.intellij.openapi.fileTypes.UnknownFileType
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.vfs.VirtualFile
 import com.intellij.psi.PsiFileFactory
@@ -32,11 +34,7 @@ import java.io.IOException
 import java.util.*
 
 fun VirtualFile.isKlibLibraryRootForPlatform(targetPlatform: TargetPlatform): Boolean {
-    // The virtual file for a library packed in a ZIP file will have path like "/some/path/to/the/file.klib!/",
-    // and therefore will be recognized by VFS as a directory (isDirectory == true).
-    // So, first, let's check the extension.
-    val extension = extension
-    if (!extension.isNullOrEmpty() && extension != KLIB_FILE_EXTENSION) return false
+    if (!isAllowableFile()) return false
 
     // run check for library root too
     // this is necessary to recognize old style KLIBs that do not have components, and report tem to user appropriately
@@ -49,6 +47,12 @@ fun VirtualFile.isKlibLibraryRootForPlatform(targetPlatform: TargetPlatform): Bo
     return children?.any { checkKlibComponent(it, requestedBuiltInsPlatform) } == true
 }
 
+private fun VirtualFile.isAllowableFile(): Boolean = when {
+    fileType == ArchiveFileType.INSTANCE -> extension == KLIB_FILE_EXTENSION
+    isDirectory -> true
+    else -> false
+}
+
 private fun checkKlibComponent(componentFile: VirtualFile, requestedBuiltInsPlatform: BuiltInsPlatform): Boolean {
     val manifestFile = componentFile.findChild(KLIB_MANIFEST_FILE_NAME)?.takeIf { !it.isDirectory } ?: return false