[FE 1.0] Fix reporting of non exhaustive when statement for whens with subject

^KT-48653 Fixed

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

@@ -1002,7 +1002,7 @@ class ControlFlowInformationProviderImpl private constructor(
                         trace.report(EXPECT_TYPE_IN_WHEN_WITHOUT_ELSE.on(element, it.typeOfDeclaration))
                     }
                 } else if (subjectExpression != null) {
-                    val subjectType = trace.getType(subjectExpression)
+                    val subjectType = WhenChecker.whenSubjectType(element, trace.bindingContext)
                     if (elseEntry != null) {
                         if (missingCases.isEmpty() && subjectType != null && !subjectType.isFlexible()) {
                             val subjectClass = subjectType.constructor.declarationDescriptor as? ClassDescriptor
@@ -1016,9 +1016,6 @@ class ControlFlowInformationProviderImpl private constructor(
                             }
                         }
                         continue
-                    }
-                    if (!usedAsExpression) {
-
                     }
                     if (!usedAsExpression) {
                         if (languageVersionSettings.supportsFeature(LanguageFeature.WarnAboutNonExhaustiveWhenOnAlgebraicTypes)) {