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/variables/accessorAndFunction.kt

@@ -0,0 +1,23 @@
+class My {
+
+    val y: Int 
+        get() {
+            var x: Int?
+            x = 3
+            return <!DEBUG_INFO_SMARTCAST!>x<!>.hashCode()
+        }
+
+    fun test() {
+        var x: Int?
+        x = 2
+        <!DEBUG_INFO_SMARTCAST!>x<!>.hashCode()
+        fun bb() {
+           var <!NAME_SHADOWING!>x<!>: Any?
+           x = 4
+           <!SMARTCAST_IMPOSSIBLE!>x<!>.hashCode()
+        }
+        x = 4
+        // Really smart cast is possible but name shadowing by bb() prevents it
+        <!SMARTCAST_IMPOSSIBLE!>x<!>.hashCode()
+    }
+}