RFR: 8305480: test/hotspot/jtreg/runtime/NMT/VirtualAllocCommitMerge.java failing on 32 bit arm [v2]

[Vladimir Petko]

> os::current_frame() is stubbed out on the Linux Arm Thumb platform [1].
> 
> This affects 'MemDetailReporter::report_virtual_memory_region()'[2] causing the trace to miss 'from  <location>' part which breaks 'test/hotspot/jtreg/runtime/NMT/VirtualAllocCommitMerge.java'.
> 
> 
> result: Failed. Execution failed: `main' threw exception: java.lang.RuntimeException: '[0x[0]*7947e000 - 0x[0]*794de000] committed 384KB from.*' missing from stdout/stderr
> 
> This PR relaxes the test assertion, as 'MemDetailReporter::report_virtual_memory_region()' as 'from' statement is only available if the current frame can be unwinded [2].
> 
> [1] https://github.com/openjdk/jdk/blob/0deb648985b018653ccdaf193dc13b3cf21c088a/src/hotspot/os_cpu/linux_arm/os_linux_arm.cpp#L219
> [2] https://github.com/openjdk/jdk/blob/aa762102e9328ca76663b56b3be6f6141b044744/src/hotspot/share/services/memReporter.cpp#L397

Vladimir Petko 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 three additional commits since the last revision:

 - Merge branch 'master' into relax-assertions
 - review comment: limit change to ARM 32 platform
 - Relax test assertion
   
   MemDetailReporter::report_virtual_memory_region() has two code paths, one containing from and without it, remove from requirement from the assertion

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/13291/files
  - new: https://git.openjdk.org/jdk/pull/13291/files/264311c1..52b1473c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13291&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13291&range=00-01

  Stats: 9258 lines in 186 files changed: 1969 ins; 6977 del; 312 mod
  Patch: https://git.openjdk.org/jdk/pull/13291.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13291/head:pull/13291

PR: https://git.openjdk.org/jdk/pull/13291