RFR: 8329840: Fix ZPhysicalMemorySegment::_end type [v2]

[Axel Boldt-Christmas]

> `ZPhysicalMemorySegment::_end` should use `zoffset_end` for its type instead of `zoffset`.
> 
> Starting a debug vm with a 16TB min heap size will crash with an invalid `zoffset` assert.
> 
> Testing with ZGC tier1-tier7 on linux x64+aarch64

Axel Boldt-Christmas has updated the pull request incrementally with one additional commit since the last revision:

  Fix whitespace

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Changes:
  - all: https://git.openjdk.org/jdk/pull/18673/files
  - new: https://git.openjdk.org/jdk/pull/18673/files/60bf14ee..ae3160d4

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=18673&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=18673&range=00-01

  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/18673.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18673/head:pull/18673

PR: https://git.openjdk.org/jdk/pull/18673