[Test] Disable UNUSED_* diagnostics in tests which are not belong to contolFlowAnalysis suite

compiler/testData/diagnostics/tests/kt34440.kt

@@ -2,7 +2,7 @@
 
 class BufferUtil {
     fun isDirect(cond: Boolean): Boolean =
-        when (<!UNUSED_EXPRESSION!>cond<!>) {
+        when (cond) {
             else -> throw Exception("${<!UNRESOLVED_REFERENCE!>buf<!>.<!SYNTAX!><!>}")
         }
     private class BufferInfo(private val type: Class<*>)