Add test for private suspend and JVM defaults

compiler/testData/codegen/box/jvm8/defaults/allCompatibility/privateSuspend.kt

@@ -0,0 +1,32 @@
+// !JVM_DEFAULT_MODE: all-compatibility
+// TARGET_BACKEND: JVM
+// JVM_TARGET: 1.8
+// WITH_COROUTINES
+// WITH_RUNTIME
+// IGNORE_BACKEND: JVM
+import helpers.*
+import kotlin.coroutines.*
+import kotlin.coroutines.intrinsics.*
+
+
+fun builder(c: suspend () -> Unit) {
+    c.startCoroutine(EmptyContinuation)
+}
+
+interface Z {
+    private suspend fun test(): String {
+        return "OK"
+    }
+
+    suspend fun test2(): String {
+        return test()
+    }
+}
+
+fun box(): String {
+    var result = "fail"
+    builder {
+        result = object : Z {}.test2()
+    }
+    return result
+}