RFR: JDK-8311870: Split CompressedKlassPointers from compressedOops.hpp

[Thomas Stuefe]

On Tue, 11 Jul 2023 11:20:19 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:

> In preparation for some Lilliput-related changes, I'd like to get some purely mechanical code moves out of the way. It would also improve separation of concerns and reduces include header bloat.
> 
> In particular, this patch does:
> 
> 1) Move `CompressedKlassPointers` from `compressedOops.(cpp|hpp|inline.hpp)` to `compressedKlass.(cpp|hpp|inline.hpp)`
> 
> 2) flatten the `NarrowPtrStruct _narrow_klass` to `address _base; int _shift` (its implicit null check member is not needed for Klass and it has little merit otherwise).
> 
> 3) moved `narrowKlass` from `oopsHierarchy.hpp` to `compressedKlass.hpp`
> 
> 4) remove `KlassAlignment` and `LogKlassAlignment` (the word-sized variants, not xxxInBytes) since they are unused
> 
> 5) Move `KlassEncodingMetaspaceMax`, `LogKlassAlignmentInBytes` and `KlassAlignmentInBytes` to compressedKlass.hpp
> 
> 6) Fixed all include issues (including existing missing includes)
> 
> 7) Fixed VM struct because of (2)
> 
> Note that nothing functional is changed.

pinging @rkennke

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

PR Comment: https://git.openjdk.org/jdk/pull/14826#issuecomment-1630864393