RFR: 8305481: gtest is_first_C_frame failing on ARM [v2]

[Vladimir Petko]

> os::current_frame() is stubbed out on the Linux Arm Thumb platform [1]
> This causes gtest 'is_first_C_frame' to fail. 
> 
> 
> [ RUN      ] os.is_first_C_frame_vm
> ./test/hotspot/gtest/runtime/test_os.cpp:890: Failure
> Value of: os::is_first_C_frame(&cur_frame)
>   Actual: true
> Expected: false
> [  FAILED  ] os.is_first_C_frame_vm (0 ms)
> 
> This pull request disables the test for ARM Thumb.
> 
> [1] https://github.com/openjdk/jdk/blob/0deb648985b018653ccdaf193dc13b3cf21c088a/src/hotspot/os_cpu/linux_arm/os_linux_arm.cpp#L219

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 two additional commits since the last revision:

 - Merge branch 'master' into disable_test_on_thumb
 - disable is_first_C_frame on ARM Thumb

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/13292/files
  - new: https://git.openjdk.org/jdk/pull/13292/files/ce26e585..1ddf4c2a

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13292&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13292&range=00-01

  Stats: 9252 lines in 185 files changed: 1964 ins; 6977 del; 311 mod
  Patch: https://git.openjdk.org/jdk/pull/13292.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13292/head:pull/13292

PR: https://git.openjdk.org/jdk/pull/13292