FIR CFG: mark variables touched by not-in-place lambdas in all scopes

compiler/testData/diagnostics/tests/smartCasts/variables/capturedByNested.kt

@@ -0,0 +1,22 @@
+// FIR_IDENTICAL
+import kotlin.contracts.*
+
+@Suppress("OPT_IN_USAGE_ERROR", "OPT_IN_USAGE_FUTURE_ERROR")
+fun exactlyOnce(f: () -> Unit) {
+    contract {
+        callsInPlace(f, InvocationKind.EXACTLY_ONCE)
+    }
+    f()
+}
+
+fun test() {
+    var s: String? = ""
+    if (s != null) {
+        val block: () -> Unit
+        exactlyOnce {
+            block = { s = null }
+        }
+        block()
+        <!SMARTCAST_IMPOSSIBLE!>s<!>.length
+    }
+}