JVM_IR KT-47326 downcast field receiver on JvmField lowering

compiler/testData/codegen/box/jvmField/kt47328_super.kt

@@ -0,0 +1,18 @@
+// TARGET_BACKEND: JVM
+// WITH_RUNTIME
+
+interface A { val x: String }
+
+open class B(@JvmField override val x: String): A
+
+open class BB(x: String) : B(x)
+
+class X(x: String) : A, BB(x) {
+    override val x: String
+        get() = super.x
+}
+
+fun box(): String {
+    val e = X("OK")
+    return e.x
+}