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/infos/SmartCasts.kt

@@ -211,9 +211,9 @@ fun f(): String {
         // a is a string, despite of being a variable
         val <!UNUSED_VARIABLE!>i<!>: String = <!DEBUG_INFO_SMARTCAST!>a<!>
         <!DEBUG_INFO_SMARTCAST!>a<!>.compareTo("f")
-        // Beginning from here a is captured in a closure so we have to be cautious
-        val <!UNUSED_VARIABLE!>f<!>: Function0<String> = { <!SMARTCAST_IMPOSSIBLE!>a<!> }
-        return <!SMARTCAST_IMPOSSIBLE!>a<!>
+        // Beginning from here a is captured in a closure but nobody modifies it
+        val <!UNUSED_VARIABLE!>f<!>: Function0<String> = { <!DEBUG_INFO_SMARTCAST!>a<!> }
+        return <!DEBUG_INFO_SMARTCAST!>a<!>
     }
     return ""
 }