[jdk17u-dev] RFR: 8352800: [PPC] OpenJDK fails to build on PPC after JDK-8350106

[Richard Reingruber]

Hi all,

This pull request contains a backport of commit [72bcd824](https://github.com/openjdk/jdk21u-dev/commit/72bcd824606d8a9bc25fb088e73de4c25738ecea) from the [openjdk/jdk21u-dev](https://git.openjdk.org/jdk21u-dev) repository.

https://github.com/openjdk/jdk17u-dev/pull/3957 depends on this backport.
It fixes build problems by including the declaration of `class os::Linux` referenced in https://github.com/openjdk/jdk17u-dev/pull/3957 .
In jdk17 os_linux.hpp cannot be included directly though. os.hpp needs to be included which includes os_linux.hpp into the declaration of `class os` (see [here](https://github.com/openjdk/jdk17u-dev/blob/78cafc3138f09de208a786b7e55bed585e42ade8/src/hotspot/share/runtime/os.hpp#L896)).

Risk is low.

Thanks, Richard.

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

Commit messages:
 - Must include os.hpp in jdk17 to access os::Linux
 - Backport 72bcd824606d8a9bc25fb088e73de4c25738ecea

Changes: https://git.openjdk.org/jdk17u-dev/pull/3949/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=3949&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8352800
  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/3949.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/3949/head:pull/3949

PR: https://git.openjdk.org/jdk17u-dev/pull/3949