Add 'mute' concept: move tests with unexpected behaviour to the corresponding folder

compiler/tests-spec/testData/diagnostics/linked/when-expression/p-11/pos/6.1.kt

@@ -64,3 +64,22 @@ fun case_6(value_1: _SealedClassMixed): String = when (value_1) {
 fun case_7(value_1: _SealedClassEmpty): String = when (value_1) {
     else -> ""
 }
+
+/*
+ CASE DESCRIPTION: Checking for not exhaustive 'when' on opposite types.
+ UNEXPECTED BEHAVIOUR: must be exhaustive
+ ISSUES: KT-22996
+ */
+fun case_8(value: _SealedClass?): String = <!NO_ELSE_IN_WHEN!>when<!> (value) {
+    is _SealedChild1, !is _SealedChild3?, <!USELESS_IS_CHECK!>is _SealedChild3?<!> -> ""
+}
+
+/*
+ CASE DESCRIPTION: Checking for not exhaustive 'when' on opposite types.
+ UNEXPECTED BEHAVIOUR: must be exhaustive
+ ISSUES: KT-22996
+ */
+fun case_9(value: _SealedClass?): String = <!NO_ELSE_IN_WHEN!>when<!> (value) {
+    is _SealedChild1, !is _SealedChild3 -> ""
+    <!USELESS_IS_CHECK!>is _SealedChild3?<!> -> ""
+}

compiler/tests-spec/testData/diagnostics/linked/when-expression/p-11/pos/8.2.kt

@@ -24,3 +24,12 @@ fun case_2(value_1: _EnumClassSingle?): String = when (value_1) {
     _EnumClassSingle.EVERYTHING -> ""
     null -> ""
 }
+
+/*
+ CASE DESCRIPTION: Checking for not exhaustive 'when' on the empty nullable enum class.
+ UNEXPECTED BEHAVIOUR
+ ISSUES: KT-26044
+ */
+fun case_3(value_1: _EnumClassEmpty?): String = <!NO_ELSE_IN_WHEN!>when<!>(value_1) {
+    null -> ""
+}

compiler/tests-spec/testData/diagnostics/linked/when-expression/p-11/pos/8.3.kt

@@ -64,3 +64,12 @@ fun case_6(value_1: _SealedClassMixed?): String = when (value_1) {
     is _SealedMixedChildObject3 -> ""
     null -> ""
 }
+
+/*
+ CASE DESCRIPTION: Checking for not exhaustive 'when' on the empty nullable sealed class (without subtypes).
+ UNEXPECTED BEHAVIOUR: must be exhaustive
+ ISSUES: KT-26044
+ */
+fun case_7(value: _SealedClassEmpty?): String = <!NO_ELSE_IN_WHEN!>when<!> (value) {
+    null -> ""
+}