[FIR] Fix collecting member candidates on receiver with smartcast

^KT-51460 Fixed
^KT-51827

compiler/testData/codegen/box/fakeOverride/fakeOverrideInAnonymousObject.kt

@@ -0,0 +1,26 @@
+// TARGET_BACKEND: JVM_IR
+interface JPanel {
+    val result: String
+}
+
+open class ActivePanel : JPanel {
+    override var result: String = ""
+
+    fun fire(event: String) {
+        result = event
+    }
+}
+
+class Test {
+    val panel: JPanel
+
+    init {
+        panel = object : ActivePanel() {}
+
+        panel.fire("OK")
+    }
+}
+
+fun box(): String {
+    return Test().panel.result
+}