Refactoring & clarification: implement new FIR tower resolver

compiler/testData/diagnostics/tests/classObjects/ClassObjectCannotAccessClassFields.fir.kt

@@ -4,6 +4,6 @@ class A() {
     val x = 1
 
     companion object {
-        val y = x
+        val y = <!UNRESOLVED_REFERENCE!>x<!>
     }
 }

compiler/testData/diagnostics/tests/classObjects/InnerClassAccessThroughEnum_after.fir.kt

@@ -21,7 +21,7 @@ enum class C {
             C.A()
             A()
             //TODO: should be resolved with error
-            this.A()
+            this.<!UNRESOLVED_REFERENCE!>A<!>()
         }
     };
 
@@ -34,7 +34,7 @@ enum class C {
 
 fun f() {
     C.E1.A
-    C.E1.A()
+    C.E1.<!UNRESOLVED_REFERENCE!>A<!>()
     C.E2.B()
 
     C.E2.O

compiler/testData/diagnostics/tests/classObjects/InnerClassAccessThroughEnum_before.fir.kt

@@ -21,7 +21,7 @@ enum class C {
             C.A()
             A()
             //TODO: should be resolved with error
-            this.A()
+            this.<!UNRESOLVED_REFERENCE!>A<!>()
         }
     };
 
@@ -34,7 +34,7 @@ enum class C {
 
 fun f() {
     C.E1.A
-    C.E1.A()
+    C.E1.<!UNRESOLVED_REFERENCE!>A<!>()
     C.E2.B()
 
     C.E2.O

compiler/testData/diagnostics/tests/classObjects/resolveFunctionInsideClassObject.fir.kt

@@ -4,6 +4,6 @@ class Test {
   fun test(): Int = 12
 
   companion object {
-    val a = test() // Check if resolver will be able to infer type of a variable
+    val a = <!UNRESOLVED_REFERENCE!>test<!>() // Check if resolver will be able to infer type of a variable
   }
 }