MUST_BE_INITIALIZED: take into account containingDeclaration's modality

^KT-58587 Fixed
Review: https://jetbrains.team/p/kt/reviews/10136

This commit is important in scope of KT-57553. It makes the migration
more smooth.

Other related tests:
- testUninitializedOrReassignedVariables
- testAugmentedAssignmentInInitializer

compiler/frontend/cfg/src/org/jetbrains/kotlin/cfg/ControlFlowInformationProviderImpl.kt

@@ -628,7 +628,7 @@ class ControlFlowInformationProviderImpl private constructor(
         val property = DescriptorToSourceUtils.descriptorToDeclaration(variableDescriptor) as? KtProperty
             ?: throw AssertionError("$variableDescriptor is not related to KtProperty")
         val setter = property.setter
-        if (variableDescriptor.modality == Modality.FINAL && (setter == null || !setter.hasBody())) {
+        if (variableDescriptor.getEffectiveModality(languageVersionSettings) == Modality.FINAL && (setter == null || !setter.hasBody())) {
             return false
         }
 
@@ -1472,3 +1472,10 @@ class ControlFlowInformationProviderImpl private constructor(
             return result
         }
 }
+
+private fun PropertyDescriptor.getEffectiveModality(languageVersionSettings: LanguageVersionSettings): Modality =
+    when (languageVersionSettings.supportsFeature(LanguageFeature.TakeIntoAccountEffectivelyFinalInMustBeInitializedCheck) &&
+            modality == Modality.OPEN && (containingDeclaration as? ClassDescriptor)?.modality == Modality.FINAL) {
+        true -> Modality.FINAL
+        false -> modality
+    }