[light classes] drop old light classes and backend: iteration #2

drop javaFileStub and fix tests

^KT-48773

analysis/symbol-light-classes/src/org/jetbrains/kotlin/light/classes/symbol/FirFakeFileImpl.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
@@ -18,7 +18,6 @@ import org.jetbrains.kotlin.psi.KtClassOrObject
 class FirFakeFileImpl(private val classOrObject: KtClassOrObject, ktClass: KtLightClass) : FakeFileForLightClass(
     classOrObject.containingKtFile,
     { if (classOrObject.isTopLevel()) ktClass else getOrCreateFirLightClass(getOutermostClassOrObject(classOrObject))!! },
-    { null }
 ) {
 
     override fun findReferenceAt(offset: Int) = ktFile.findReferenceAt(offset)

analysis/symbol-light-classes/src/org/jetbrains/kotlin/light/classes/symbol/classes/FirLightClassForFacade.kt

@@ -172,7 +172,6 @@ class FirLightClassForFacade(
     private val packageClsFile = FakeFileForLightClass(
         firstFileInFacade,
         lightClass = { this },
-        stub = { null },
         packageFqName = packageFqName
     )