[8] Review request for 8004970, 8004971, and 8006817: implement serialization in lambda metafactory and metafactory fix

[Brian Goetz]

> in MethodHandleInfo:
>    - getReferenceKindString should not be public, it's a detail of
> implementation.

The purpose of this call is so that clients who use MHI to crack an MH 
can turn it into an accurate string representation, such as what javap 
does when dumping constant pools with MH constants in it.  Otherwise, 
everyone has to write their own switch based on what is in the JLS.

> in SerializedLambda:
>     - I think it should declare a serialUID, so you don't need a ad-hoc
> versioning.

Agreed.

>       (to answer to the question line 235)
>     - Also does the constructor
> SerializedLambda(Class ,MethodHandle,MethodHandle,MethodType,Object[])
>       still used ?

Not in the JDK.  Robert, what about compiler-generated code?  If not 
used, we should remove it.