Disable highlighting for decompiled Kotlin files (KT-27284)

#KT-27284 Fixed

idea/src/org/jetbrains/kotlin/idea/highlighter/KotlinDefaultHighlightingSettingsProvider.kt

@@ -9,12 +9,14 @@ import com.intellij.codeInsight.daemon.impl.analysis.DefaultHighlightingSettingP
 import com.intellij.codeInsight.daemon.impl.analysis.FileHighlightingSetting
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.vfs.VirtualFile
+import org.jetbrains.kotlin.idea.internal.isKotlinDecompiledFile
 import org.jetbrains.kotlin.idea.util.ProjectRootsUtil
 
 class KotlinDefaultHighlightingSettingsProvider : DefaultHighlightingSettingProvider() {
     override fun getDefaultSetting(project: Project, file: VirtualFile): FileHighlightingSetting? {
         return when {
             ProjectRootsUtil.isLibraryFile(project, file) -> FileHighlightingSetting.SKIP_INSPECTION
+            file.isKotlinDecompiledFile -> FileHighlightingSetting.SKIP_HIGHLIGHTING
             else -> null
         }
     }

idea/src/org/jetbrains/kotlin/idea/internal/KotlinDecompilerAdapter.kt

@@ -11,6 +11,7 @@ import com.intellij.openapi.progress.ProgressIndicator
 import com.intellij.openapi.progress.ProgressManager
 import com.intellij.openapi.progress.Task
 import com.intellij.openapi.ui.Messages
+import com.intellij.openapi.util.Key
 import com.intellij.openapi.util.io.FileUtil
 import com.intellij.openapi.vfs.VfsUtil
 import com.intellij.openapi.vfs.VirtualFile
@@ -18,6 +19,7 @@ import com.intellij.openapi.vfs.VirtualFileManager
 import com.intellij.openapi.vfs.ex.dummy.DummyFileSystem
 import org.jetbrains.kotlin.idea.util.application.runWriteAction
 import org.jetbrains.kotlin.psi.KtFile
+import org.jetbrains.kotlin.psi.NotNullableUserDataProperty
 
 fun showDecompiledCode(sourceFile: KtFile) {
     ProgressManager.getInstance().run(KotlinBytecodeDecompilerTask(sourceFile))
@@ -44,11 +46,13 @@ class KotlinBytecodeDecompilerTask(val file: KtFile) : Task.Backgroundable(file.
                     return@runWriteAction
                 }
 
-                val root = getOrCreateDummyRoot()
+                val root: VirtualFile = getOrCreateDummyRoot()
                 val decompiledFileName = FileUtil.getNameWithoutExtension(file.name) + ".decompiled.java"
                 val result = DummyFileSystem.getInstance().createChildFile(null, root, decompiledFileName)
                 VfsUtil.saveText(result, decompiledText)
 
+                result.isKotlinDecompiledFile = true
+
                 OpenFileDescriptor(file.project, result).navigate(true)
             }
         }
@@ -58,6 +62,8 @@ class KotlinBytecodeDecompilerTask(val file: KtFile) : Task.Backgroundable(file.
 val KOTLIN_DECOMPILED_FOLDER = "kotlinDecompiled"
 val KOTLIN_DECOMPILED_ROOT = "dummy://$KOTLIN_DECOMPILED_FOLDER"
 
+var VirtualFile.isKotlinDecompiledFile: Boolean by NotNullableUserDataProperty(Key.create("IS_KOTLIN_DECOMPILED_FILE"), false)
+
 fun getOrCreateDummyRoot(): VirtualFile =
     VirtualFileManager.getInstance().refreshAndFindFileByUrl(KOTLIN_DECOMPILED_ROOT) ?:
        DummyFileSystem.getInstance().createRoot(KOTLIN_DECOMPILED_FOLDER)