Generate private suspend function in JVM as package-private

It helps to simplify implementation of generating state machines
into the named functions' bodies but of course has some flaws:
1. They may be called from the same package in Java
2. It may lead to problems when declaring clashing descriptor
in an inheritor

This change must be reverted at some moment, or these flaws
should be fixed in some other way

 #KT-17585 In Progress
 #KT-17584 Open

compiler/backend/src/org/jetbrains/kotlin/codegen/AsmUtil.java

@@ -395,6 +395,10 @@ public class AsmUtil {
             return null;
         }
 
+        if (memberDescriptor instanceof FunctionDescriptor && ((FunctionDescriptor) memberDescriptor).isSuspend()) {
+            return NO_FLAG_PACKAGE_PRIVATE;
+        }
+
         // the following code is only for PRIVATE visibility of member
         if (memberDescriptor instanceof ConstructorDescriptor) {
             if (isEnumEntry(containingDeclaration)) {