Minor. Add test to check fallback

compiler/testData/codegen/bytecodeListing/inlineClasses/stdlibManglingIn1430/old.kt

@@ -1,4 +1,5 @@
 // KOTLIN_CONFIGURATION_FLAGS: +JVM.USE_OLD_INLINE_CLASSES_MANGLING_SCHEME
+// !LANGUAGE: -MangleClassMembersReturningInlineClasses
 // FILE: 1.kt
 package test
 

compiler/testData/compileKotlinAgainstKotlin/inlineClassesOldMangling.kt

@@ -0,0 +1,28 @@
+// !LANGUAGE: +InlineClasses
+// IGNORE_BACKEND_FIR: JVM_IR
+// FILE: 1.kt
+// KOTLIN_CONFIGURATION_FLAGS: +JVM.USE_OLD_INLINE_CLASSES_MANGLING_SCHEME
+package test
+
+inline class IC(val s: String)
+
+fun ordinary(s: String, ic: IC): String = s + ic.s
+
+suspend fun suspend(s: String, ic: IC): String = s + ic.s
+
+// FILE: 2.kt
+import kotlin.coroutines.*
+import test.*
+
+fun builder(c: suspend () -> Unit) {
+    c.startCoroutine(Continuation(EmptyCoroutineContext) {})
+}
+
+fun box(): String {
+    var res = ordinary("O", IC("K"))
+    if (res != "OK") return "FAIL 1: $res"
+    builder {
+        res = suspend("O", IC("K"))
+    }
+    return res
+}