[FIR] Introduce new algorithm for building CFG for declarations

compiler/testData/diagnostics/tests/smartCasts/kt32358_1.fir.kt

@@ -13,5 +13,5 @@ fun myFun() {
     val myParent = MyParent()
     myParent.child?.nullableString ?: run { return }
 
-    myParent.child.<!INAPPLICABLE_CANDIDATE!>notNull<!>   // <- No smart cast in plugin
+    myParent.child.notNull   // <- No smart cast in plugin
 }

compiler/testData/diagnostics/tests/smartCasts/kt32358_2.fir.kt

@@ -17,5 +17,5 @@ fun smartIt(p1: String?, p2: String?) {
     p1.<!INAPPLICABLE_CANDIDATE!>length<!>
 
     p2 ?: callItContracted { return }
-    p2.<!INAPPLICABLE_CANDIDATE!>length<!>
+    p2.length
 }

compiler/testData/diagnostics/tests/smartCasts/loops/doWhileLiteral.fir.kt

@@ -6,5 +6,5 @@ public fun foo(p: String?): Int {
         p!!.length
     } while (!x())
     // Literal is not called so p.length is unsafe
-    return p.<!INAPPLICABLE_CANDIDATE!>length<!>
+    return p.length
 }