More tests on casts on receiver of inline class type

compiler/testData/codegen/box/inlineClasses/inlineExtLambdaInInlineClassFun2.kt

@@ -0,0 +1,10 @@
+// !LANGUAGE: +InlineClasses
+// IGNORE_BACKEND: JVM_IR
+
+inline fun <T> T.runInlineExt(fn: T.() -> String) = fn()
+
+inline class R(private val r: String) {
+    fun test() = runInlineExt { r }
+}
+
+fun box() = R("OK").test()