[NI] Continue resolution after unstable smart cast on receiver

The old inference cosideres candidates with unstable smartcast on
receiver unsuccessful, therefore another one may be selected.
KT-36264

compiler/testData/diagnostics/tests/smartCasts/elvis/impossible.kt

@@ -18,7 +18,7 @@ fun foo(list: StringList, arg: Unstable) {
     list.remove(arg.first)
     if (arg.first?.isEmpty() ?: false) {
         // Should be still resolved to extension, without smart cast or smart cast impossible
-        list.remove(<!OI;SMARTCAST_IMPOSSIBLE!>arg.first<!>)
+        list.remove(<!NI;SMARTCAST_IMPOSSIBLE, SMARTCAST_IMPOSSIBLE!>arg.first<!>)
     }
 }
 
@@ -36,6 +36,6 @@ fun bar(list: BooleanList, arg: UnstableBoolean) {
     list.remove(arg.first)
     if (arg.first ?: false) {
         // Should be still resolved to extension, without smart cast or smart cast impossible
-        list.remove(<!OI;SMARTCAST_IMPOSSIBLE!>arg.first<!>)
+        list.remove(<!NI;SMARTCAST_IMPOSSIBLE, SMARTCAST_IMPOSSIBLE!>arg.first<!>)
     }
 }