RFR: 8346609: Improve MemorySegment.toString [v6]

[Per Minborg]

> This PR proposes to improve the current `MemorySegment.toString()` method from:
> 
> `MemorySegment{ address: 0x60000264c540, byteSize: 8 }`
> 
> to
> 
> `MemorySegment{ native, address: 0x60000264c540, byteSize: 8}`
> 
> Tests passes tier1-tier3

Per Minborg has updated the pull request incrementally with one additional commit since the last revision:

  Rename variable

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/22826/files
  - new: https://git.openjdk.org/jdk/pull/22826/files/dea2fc31..ad0fd941

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22826&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22826&range=04-05

  Stats: 5 lines in 1 file changed: 0 ins; 0 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/22826.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22826/head:pull/22826

PR: https://git.openjdk.org/jdk/pull/22826