FIR checkers: report SMARTCAST_IMPOSSIBLE

compiler/testData/diagnostics/tests/nullabilityAndSmartCasts/unstableSmartcastWhenOpenGetterWithOverloading.fir.kt

@@ -1,15 +0,0 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER
-
-interface Ctx
-class CtxImpl : Ctx {
-    fun doJob(a: Int) {}
-    fun doJob(s: String) {}
-}
-
-open class Test(open val ctx: Ctx) {
-    fun test() {
-        when (ctx) {
-            is CtxImpl -> ctx.<!UNRESOLVED_REFERENCE!>doJob<!>(2)
-        }
-    }
-}

compiler/testData/diagnostics/tests/nullabilityAndSmartCasts/unstableSmartcastWhenOpenGetterWithOverloading.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // !DIAGNOSTICS: -UNUSED_PARAMETER
 
 interface Ctx

compiler/testData/diagnostics/tests/nullabilityAndSmartCasts/unstableSmartcastWithOverloadedExtensions.fir.kt

@@ -1,14 +0,0 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER
-
-class A
-class B
-
-fun A.foo(a: A) {}
-fun A.foo(b: B) {}
-var a: A? = null
-
-fun smartCastInterference(b: B) {
-    if (a != null) {
-        a<!UNSAFE_CALL!>.<!>foo(b)
-    }
-}

compiler/testData/diagnostics/tests/nullabilityAndSmartCasts/unstableSmartcastWithOverloadedExtensions.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // !DIAGNOSTICS: -UNUSED_PARAMETER
 
 class A