Fix for-in iterator over list of boxed inline class values

#KT-25325 Fixed

compiler/testData/codegen/box/inlineClasses/iterateOverListOfInlineClassValues.kt

@@ -0,0 +1,16 @@
+// !LANGUAGE: +InlineClasses
+// WITH_RUNTIME
+// IGNORE_BACKEND: JVM_IR
+// IGNORE_BACKEND: JS_IR
+
+inline class Foo(val arg: String)
+
+fun box(): String {
+    val ls = listOf(Foo("abc"), Foo("def"))
+    var res = ""
+    for (el in ls) {
+        res += el.arg
+    }
+
+    return if (res != "abcdef") "Fail" else "OK"
+}