RFR: JDK-8322648: Improve class initialization barrier in TemplateTable::_new for PPC

[Martin Doerr]

On Mon, 22 Jan 2024 12:26:51 GMT, Varada M <varadam at openjdk.org> wrote:

> ppc port implementation of https://github.com/openjdk/jdk/pull/17006
> 
> Fastdebug and Release : build and tier1 testing successful.
> 
> JBS Issue : [JDK-8322648](https://bugs.openjdk.org/browse/JDK-8322648)

You need to adapt the succeeding code and remove the dependent `crnand` instruction. I suggest to use `cmpdi(CCR0, Rscratch, InstanceKlass::fully_initialized);`.

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Changes requested by mdoerr (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/17518#pullrequestreview-1841412353