KT-6118 Redundant type cast can be not redundant?

#KT-6118 Fixed

compiler/testData/diagnostics/tests/dataFlow/assignment/assignToNewVal.kt

@@ -0,0 +1,10 @@
+fun test(a: Any?) {
+    if (a == null) return
+    <!DEBUG_INFO_SMARTCAST!>a<!>.hashCode()
+
+    val b = a
+    <!DEBUG_INFO_SMARTCAST!>b<!>.hashCode()
+
+    val c: Any? = a
+    c<!UNSAFE_CALL!>.<!>hashCode()
+}