[FIR TEST] Update diagnostic spec test data

compiler/tests-spec/testData/diagnostics/linked/expressions/when-expression/p-6/neg/1.2.fir.kt

@@ -3,7 +3,7 @@
 // TESTCASE NUMBER: 1
 fun case_1(value_1: Any, value_2: Int): String {
     when (value_1) {
-        is value_2 -> return ""
+        is <!UNRESOLVED_REFERENCE!>value_2<!> -> return ""
     }
 
     return ""

compiler/tests-spec/testData/diagnostics/linked/type-system/type-contexts-and-scopes/inner-and-nested-type-contexts/p-1/neg/2.1.fir.kt

@@ -8,14 +8,14 @@ class Case1<AT>(val x: AT) {
 
     class B(val y: AT) {
         fun case1() {
-            val k: AT
+            val k: <!UNRESOLVED_REFERENCE!>AT<!>
         }
     }
 
     class C() {
         fun case1(x: Any) {
             when (x) {
-                is AT -> println("at")
+                is <!UNRESOLVED_REFERENCE!>AT<!> -> println("at")
                 else -> println("else")
             }
         }