Deprecate simplification of complex boolean constant expressions in whens and loops

^KT-39883 In Progress

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

@@ -1,3 +1,5 @@
+// FIR_IDENTICAL
+// !LANGUAGE: +ProhibitSimplificationOfNonTrivialConstBooleanExpressions
 /*
  * KOTLIN DIAGNOSTICS SPEC TEST (NEGATIVE)
  *
@@ -11,7 +13,7 @@
 // See also: KT-3743
 fun foo(arg: Boolean): String {
     // Must be exhaustive
-    return when(arg) {
+    return <!NO_ELSE_IN_WHEN!>when<!>(arg) {
         2 == 2 -> "truth"
         2 == 1 -> "falsehood"
     }