Exhaustive whens without else and 'Nothing' as the result are considered 'implicit exhaustive'

compiler/testData/diagnostics/tests/when/ExhaustiveBreakContinue.kt

@@ -2,11 +2,11 @@ enum class Color { RED, GREEN, BLUE }
 
 fun foo(arr: Array<Color>): Color {
     loop@ for (color in arr) {
-        when (color) {
+        <!DEBUG_INFO_IMPLICIT_EXHAUSTIVE!>when (color) {
             Color.RED -> return color
             Color.GREEN -> break@loop
             Color.BLUE -> if (arr.size == 1) return color else continue@loop
-        }
+        }<!>
         // Unreachable
         <!UNREACHABLE_CODE!>return Color.BLUE<!>
     }

compiler/testData/diagnostics/tests/when/ExhaustivePlatformEnumStatement.kt

@@ -13,8 +13,8 @@ public enum J {
 // FILE: K.kt
 
 fun foo(): Int {
-    when (<!WHEN_ENUM_CAN_BE_NULL_IN_JAVA!>J.create()<!>) {
+    <!DEBUG_INFO_IMPLICIT_EXHAUSTIVE!>when (<!WHEN_ENUM_CAN_BE_NULL_IN_JAVA!>J.create()<!>) {
         J.A -> return 1
         J.B -> return 2
-    }
+    }<!>
 }

compiler/testData/diagnostics/tests/when/ExhaustiveReturn.kt

@@ -3,11 +3,11 @@ enum class Direction {
 }
 
 fun foo(dir: Direction): Int {
-    when (dir) {
+    <!DEBUG_INFO_IMPLICIT_EXHAUSTIVE!>when (dir) {
         Direction.NORTH -> return 1
         Direction.SOUTH -> return 2
         Direction.WEST  -> return 3
         Direction.EAST  -> return 4
-    }
+    }<!>
     // See KT-1882: no return is needed at the end
 }

compiler/testData/diagnostics/tests/when/ExhaustiveReturnThrow.kt

@@ -3,12 +3,12 @@ enum class Direction {
 }
 
 fun foo(dir: Direction): Int {
-    when (dir) {
+    <!DEBUG_INFO_IMPLICIT_EXHAUSTIVE!>when (dir) {
         Direction.NORTH -> return 1
         Direction.SOUTH -> throw AssertionError("!!!")
         Direction.WEST  -> return 3
         Direction.EAST  -> return 4
-    }
+    }<!>
     // Error: Unreachable code. Return is not required.
     <!UNREACHABLE_CODE!>if (dir == Direction.SOUTH) return 2<!>
 }