RFR 8246095: Tweaks to memory access API

[Paul Sandoz]

+1 (reviewed on panama-dev)

Paul.

> On May 28, 2020, at 2:25 PM, Maurizio Cimadamore <maurizio.cimadamore at oracle.com> wrote:
> 
> Hi,
> this followup change includes a number of tweaks that have been added to the memory access API while we were in the process of integrating it. Most of them have been contributed by Chris (thanks!), and are all listed in great details in the CSR below:
> 
> https://bugs.openjdk.java.net/browse/JDK-8246096
> 
> Implementation-wise it should be all relatively straightforward - apart for the bit of surgery on lambda forms which was required to add a new kind of lambda forms to 'collect' return values. For now this method handle adaptation is package private, and can only be used by MemoryHandles::filterValues - but, if people find it useful, we might consider adding it to the MethodHandle standard combinator toolbox.
> 
> Cheers
> Maurizio
> 
> 
> Webrev:
> 
> http://cr.openjdk.java.net/~mcimadamore/8246095_v1/webrev/
> 
> Javadoc:
> 
> http://cr.openjdk.java.net/~mcimadamore/8246095_v1/javadoc/jdk/incubator/foreign/package-summary.html
> 
> Specdiff:
> 
> http://cr.openjdk.java.net/~mcimadamore/8246095_v1/specdiff/overview-summary.html
>