[FE] Make whens on expect sealed classes and enums not exhaustive

idea/src/org/jetbrains/kotlin/idea/quickfix/AddWhenRemainingBranchesFix.kt

@@ -90,8 +90,10 @@ class AddWhenRemainingBranchesFix(
             (whenCloseBrace.prevSibling as? PsiWhiteSpace)?.replace(psiFactory.createNewLine())
             for (case in missingCases) {
                 val branchConditionText = when (case) {
-                    WhenMissingCase.Unknown, WhenMissingCase.NullIsMissing, is WhenMissingCase.BooleanIsMissing ->
-                        case.branchConditionText
+                    WhenMissingCase.Unknown,
+                    WhenMissingCase.NullIsMissing,
+                    is WhenMissingCase.BooleanIsMissing,
+                    is WhenMissingCase.ConditionTypeIsExpect -> case.branchConditionText
                     is WhenMissingCase.IsTypeCheckIsMissing ->
                         if (case.isSingleton) {
                             ""
@@ -126,4 +128,4 @@ class AddWhenRemainingBranchesFix(
             }
         }
     }
-}
+}

idea/testData/multiplatform/whenExhaustivenessForSealed/common/common.kt

@@ -2,6 +2,6 @@ expect sealed class <!LINE_MARKER("descr='Is subclassed by CommonAImplTestClass
 class CommonImplTestClass: TestClass()
 
 
-fun checkCommon(t: TestClass): Int = when (t) {
+fun checkCommon(t: TestClass): Int = <!EXPECT_TYPE_IN_WHEN_WITHOUT_ELSE, NO_ELSE_IN_WHEN!>when<!> (t) {
     is CommonImplTestClass -> 0
 }