RFR: 8281946: VM.native_memory should report size of shareable memory [v5]

[Matias Saavedra Silva]

> The native memory reporting has been improved to also include the amount of shareable (read only) data. Verified with test tiers 1,2, and 4.
> 
> Sample output:
> 
> Total: reserved=33890498670, committed=2360907886, readonly=8315472
>        malloc: 75159662 #26118
>        mmap:   reserved=33815339008, committed=2285748224, readonly=8315472
> .............
> -        Shared class space (reserved=16777216, committed=13545472, readonly=8315472)
>                             (mmap: reserved=16777216, committed=13545472) 
>  
> -               Arena Chunk (reserved=441792, committed=441792)
>                             (malloc=441792)

Matias Saavedra Silva has updated the pull request incrementally with one additional commit since the last revision:

  Reverted and ajusted test

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/11401/files
  - new: https://git.openjdk.org/jdk/pull/11401/files/aaac6856..255da9e9

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=11401&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11401&range=03-04

  Stats: 43 lines in 2 files changed: 9 ins; 28 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/11401.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11401/head:pull/11401

PR: https://git.openjdk.org/jdk/pull/11401