Elvis DFA: now only left part is taken into account #KT-9100 Fixed

I had to fix a few incorrect tests using something like x!! in Elvis right part, and also one bug in our code

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

@@ -0,0 +1,9 @@
+// Based on KT-9100
+fun test(x: Any?, y: Any?): Any {
+    val z = x ?: y!!
+    y<!UNSAFE_CALL!>.<!>hashCode()
+    // !! / ?. is necessary here, because y!! above may not be executed
+    y?.hashCode()
+    y!!.hashCode()
+    return z
+}