RFR: JDK-8322475: Extend printing for System.map [v2]

[Thomas Stuefe]

> This is an expansion on the new `System.map` command introduced with JDK-8318636.
> 
> We now print valuable information per memory region, such as:
> 
> - the actual resident set size
> - the actual number of huge pages
> - the actual used page size
> - the THP state of the region (was advised, is eligible, uses THP, ...)
> - whether the region is shared
> - whether the region had been committed (backed by swap)
> - whether the region has been swapped out.
> 
> Example output:
> 
> 
> from                 to                       size        rss    hugetlb pgsz prot notes            vm info/file                                                                                                                                                                    
> 0x00000000c0000000 - 0x00000000ffe00000 1071644672          0    4194304 2M   rw-p huge             JAVAHEAP /anon_hugepage                                                                                                                                                         
> 0x00000000ffe00000 - 0x0000000100000000    2097152          0          0 2M   rw-p huge             JAVAHEAP /anon_hugepage                                                                                                                                                         
> 0x0000558016b67000 - 0x0000558016b68000       4096       4096          0 4K   r--p                  /shared/projects/openjdk/jdk-jdk/output-fastdebug/images/jdk/bin/java
> 0x0000558016b68000 - 0x0000558016b69000       4096       4096          0 4K   r-xp                  /shared/projects/openjdk/jdk-jdk/output-fastdebug/images/jdk/bin/java
> 0x00007f3a749f2000 - 0x00007f3a74c62000    2555904    2555904          0 4K   rwxp                  CODE(CodeHeap 'profiled nmethods')                               
> 0x00007f3a74c62000 - 0x00007f3a7be51000  119468032          0          0 4K   ---p nores            CODE(CodeHeap 'profiled nmethods')                               
> 0x00007f3a7be51000 - 0x00007f3a7c1c1000    3604480    3604480          0 4K   rwxp                  CODE(CodeHeap 'profiled nmethods')                               
> 0x00007f3a7c1c1000 - 0x00007f3a7c592000    4001792          0          0 4K   ---p nores            CODE(CodeHeap 'non-nmethods')                                    
> 0x00007f3a7c592000 - 0x00007f3a7c802000    2555904    2555904          0 4K   rwxp                  CODE(CodeHeap 'non-profiled nmethods')                           
> 0x00007f3a7c802000 - 0x00007f3a839f200...

Thomas Stuefe has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains six additional commits since the last revision:

 - wip
 - wip
 - wip
 - wip
 - Merge branch 'master' into System.maps-more-info
 - Extend System.map on Linux

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/17158/files
  - new: https://git.openjdk.org/jdk/pull/17158/files/f9ee2c2f..db79ce06

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17158&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17158&range=00-01

  Stats: 105599 lines in 3577 files changed: 54098 ins; 27337 del; 24164 mod
  Patch: https://git.openjdk.org/jdk/pull/17158.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17158/head:pull/17158

PR: https://git.openjdk.org/jdk/pull/17158