RFR: 8291945: Add OSInfo API for static OS information

[Ioi Lam]

On Fri, 5 Aug 2022 04:13:12 GMT, David Holmes <dholmes at openjdk.org> wrote:

>> As suggested by @tstuefe in the review of #9600, many of the `os` APIs simply return a value that was initialized during VM start up. E.g., `os::vm_page_size()`. I have added a new class `OSInfo` for managing such info
>> 
>> - Simplifies the per-OS implementation
>> - Make the "init-only-once" check consistent
>> - In some cases, the simpler `OSInfo` class can be used in lieu of the more complex `os` class. This improves HotSpot build time (e.g., relocInfo.hpp).
>> 
>> Note: I moved only 2 fields in this PR as a first step. If this works well I plan to move more fields in the future.
>
> src/hotspot/share/runtime/stackValue.hpp line 32:
> 
>> 30: 
>> 31: class BasicLock;
>> 32: class frame;
> 
> Seems unrelated to this change. ?/

This file was indirectly including frame.hpp via os.hpp. Since I removed os.hpp from this file, I needed to add a declaration for the `frame` class.

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PR: https://git.openjdk.org/jdk/pull/9758