Preliminary declaration visitor for estimating local variable's predictability for smart casts

Predictability estimation algorithm is completely new, but backward compatibility should present.
A large set of tests. Some updated tests.
Smart casts allowed for captured variables if they are not modified in closure #KT-9051 Fixed
Also #KT-8643 Fixed
Also #KT-7976 Fixed
Correct handling of lambda arguments in functions #KT-9143 Fixed

compiler/testData/diagnostics/tests/smartCasts/varInAccessor.kt

@@ -0,0 +1,17 @@
+var x: Int = 0
+    get() {
+        var y: Int? = null
+        if (y != null) {
+            return <!DEBUG_INFO_SMARTCAST!>y<!>.hashCode()
+        }
+        return field
+    }
+    set(param) {
+        var y: Int? = null
+        if (y != null) {
+            field = <!DEBUG_INFO_SMARTCAST!>y<!>.hashCode()
+        }
+        else {
+            field = param
+        }
+    }