RFR: 8343188: Investigate ways to simplify MemorySegment::ofBuffer

[Per Minborg]

On Wed, 30 Oct 2024 18:36:37 GMT, Maurizio Cimadamore <mcimadamore at openjdk.org> wrote:

>> This PR proposes to improve `MemorySegment::ofBuffer` making it more amenable to inlining and generally improving performance.
>> 
>> Testing successfully on tier1-3
>
> src/java.base/share/classes/jdk/internal/foreign/AbstractMemorySegmentImpl.java line 541:
> 
>> 539: 
>> 540:     @ForceInline
>> 541:     private static AbstractMemorySegmentImpl arrayFreeSegment(Buffer b, long offset, long length) {
> 
> the names `arrayFreeSegment` and `arrayBackedSegments` seem a bit confusing. I'd suggest `ofDirectBuffer` and `ofHeapBuffer`

I called them that initially but there is a subtle difference; there are heap buffers that are not backed by an array. The name arrayFreeSegment could better be arrayLessSegment.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/21764#discussion_r1823903044