Control-Flow Analysis: Reuse pseudo-value information for unused expression analysis

compiler/testData/diagnostics/tests/thisAndSuper/QualifiedThis.kt

@@ -1,9 +1,9 @@
 // FILE: f.kt
 class A() {
   fun foo() : Unit {
-    this@A
+    <!UNUSED_EXPRESSION!>this@A<!>
     this<!UNRESOLVED_REFERENCE!>@a<!>
-    this
+    <!UNUSED_EXPRESSION!>this<!>
   }
 
   val x = this@A.foo()

compiler/testData/diagnostics/tests/thisAndSuper/superIsNotAnExpression.kt

@@ -5,7 +5,7 @@ fun notAnExpression() {
     if (<!SUPER_IS_NOT_AN_EXPRESSION!>super<!>) {} else {} // not an expression
     val <!UNUSED_VARIABLE!>x<!> = <!SUPER_IS_NOT_AN_EXPRESSION!>super<!> // not an expression
     when (1) {
-        <!SUPER_IS_NOT_AN_EXPRESSION!>super<!> -> 1 // not an expression
+        <!SUPER_IS_NOT_AN_EXPRESSION!>super<!> -> <!UNUSED_EXPRESSION!>1<!> // not an expression
         else -> {}
     }