RFR: 8229147: Linux os::create_thread() overcounts guardpage size with newer glibc (>=2.27) [v2]

[David Holmes]

> We can now detect whether glibc includes the guard pages as part of the requested stack size or not, and so only need to make adjustments when glibc requires it.
> 
> The intent was to use a local variable as the "flag" but unfortunately it is also needed in os_posix.cpp so I had to make it part of the os::Linux API.
> 
> See bug report (and related) for details.
> 
> Testing:
>   - Manually checked log output for stack sizes and boundaries on systems with and without the glibc fix. (Again see JBS issue)
>   -  Tiers 1-3 sanity
> Thanks

David Holmes has updated the pull request incrementally with one additional commit since the last revision:

  Review comments

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Changes:
  - all: https://git.openjdk.org/jdk/pull/13571/files
  - new: https://git.openjdk.org/jdk/pull/13571/files/abcf253a..7d3d72c6

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13571&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13571&range=00-01

  Stats: 42 lines in 3 files changed: 14 ins; 11 del; 17 mod
  Patch: https://git.openjdk.org/jdk/pull/13571.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13571/head:pull/13571

PR: https://git.openjdk.org/jdk/pull/13571