RFR: 8331733: [PPC64] saving and restoring CR is not needed at most places

[Martin Doerr]

On Fri, 31 May 2024 08:56:36 GMT, Varada M <varadam at openjdk.org> wrote:

> PPC64 uses save/restore CR less often. Only LR is critical, CR is mainly needed for native-to-Java calls.
> Fastdebug: build and tier1 testing successful. [unrelated failures]

Please make xBarrierSetAssembler_ppc.cpp consistent with the normal BarrierSetAssembler. "// NOP. Conditions registers are covered by save_LR_CR" should get replaced, too.
Saving and restoring CR in `RegisterSaver::push_frame_reg_args_and_save_live_registers` and `RegisterSaver::restore_live_registers_and_pop_frame` are not needed, either.
Otherwise, this PR looks good to me. I'll run tests. (Will retest when you make updates.)

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PR Comment: https://git.openjdk.org/jdk/pull/19494#issuecomment-2147765836