FIR DFA: when removing a variable, move type statements about dependents

val c = C("...")
  val d = c
  if (c.x == null) return
  c.x.length // c.x has type String
  d.x.length // d.x -> c.x through d -> c
  c = C(null) // remove alias d -> c
  d.x.length // info from c.x moved to d.x

^KT-54824 Fixed

compiler/testData/diagnostics/tests/smartCasts/variables/reassignedDependency.fir.kt

@@ -73,5 +73,5 @@ fun test5() {
     c = C(null)
     x.length // ok
     c.x<!UNSAFE_CALL!>.<!>length // bad
-    d.x<!UNSAFE_CALL!>.<!>length // ok
+    d.x.length // ok
 }