RFR: 8366984: Remove delay slot support

[Daniel Jeliński]

On Tue, 9 Sep 2025 09:03:18 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> SPARC was the only supported architecture that uses a delay slot. The SPARC port was removed in JDK 15, and the code is effectively dead. Let's remove it.
>> 
>> The changes are no-op on all architectures that do not use delay slots. I still tested tier 1-5 on mach5, no related failures.
>
> src/hotspot/share/adlc/adlparse.cpp line 1394:
> 
>> 1392:           parse_err(SYNERR, "Using obsolete token, branch_has_delay_slot");
>> 1393:           break;
>> 1394:         }
> 
> I'm curious: why do you add that special warning? It would fail later anyway, right? Are we expecting anyone to parse things produced by different versions?

I took my inspiration from earlier work on adlc (see 6e35bcbf038cec0210c38428a8e1c233e102911a or 3f9c8a39201644952c6d07b97695a5a7ef918622), but I don't mind removing these warnings and the related code block entirely.

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PR Review Comment: https://git.openjdk.org/jdk/pull/27119#discussion_r2332667364