RFR: 8366272: The os::xxx APIs do not manage errno correctly [v6]

[Anton Artemov]

> Hi, please consider the following changes:
> 
> In this PR the handling of `errno` is improved by inspection of the codebase and fixing potential overwrites of `errno` by other methods. Potential overwrites are addressed using `ErrnoPreserver` functionality where necessary. 
> 
> Tested in tiers 1 - 5.

Anton Artemov 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:

 - Merge remote-tracking branch 'origin/master' into JDK-8366272-the-os-xxx-api-do-not-manage-errno-correctly
 - 8366272: Fixed whitespaces.
 - 8366272: Addressed reviewer's comments.
 - 8366272: Addressed reviewer's comments.
 - Merge remote-tracking branch 'origin/master' into JDK-8366272-the-os-xxx-api-do-not-manage-errno-correctly
 - 8366272: Improved errno management in os:xxx methods

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/28086/files
  - new: https://git.openjdk.org/jdk/pull/28086/files/bc0c45f7..6097b291

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=28086&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=28086&range=04-05

  Stats: 21464 lines in 497 files changed: 12414 ins; 6894 del; 2156 mod
  Patch: https://git.openjdk.org/jdk/pull/28086.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28086/head:pull/28086

PR: https://git.openjdk.org/jdk/pull/28086