RFR: 8366272: The os::xxx APIs do not manage errno correctly [v3]

[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 incrementally with one additional commit since the last revision:

  8366272: Addressed reviewer's comments.

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/28086/files
  - new: https://git.openjdk.org/jdk/pull/28086/files/e40afdb2..5f7ad209

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=28086&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=28086&range=01-02

  Stats: 18 lines in 2 files changed: 3 ins; 11 del; 4 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