Serialization considerations

[pshipton]

See https://bugs.openjdk.org/browse/JDK-8302111

All the serialized classes implemented by OpenJ9 should be checked and corrected if necessary.

"
Essentially, deserialization is a form of object construction and should enforce the same data validation and consistency checks as enforced by the constructor(s). Thus, additional checks may be needed when deserializing the objects to ensure that values failing the constructor check are rejected during deserialization as well.
"

[pshipton]

@tajila fyi

[hangshao0]

Checked the OpenJ9 implemented Serializable JCL classes: MethodType, StringBuffer, StringBuilder, Throwable. We should be fine.