RFR: 8302070: Factor null-check into load_klass() calls

[Paul Hohensee]

On Wed, 8 Feb 2023 12:55:29 GMT, Roman Kennke <rkennke at openjdk.org> wrote:

> In several asm routines, a pattern like the following can be found:
> 
>         __ null_check(obj, oopDesc::klass_offset_in_bytes());
>         __ load_klass(klass, obj, tmp);
> 
> The null-check logically belongs into load_klass(), though. This becomes apparent in Lilliput, where the klass-offset is different, depending on whether or not Lilliput is enabled.
> 
> Testing:
>  - [x] tier1 x86_64
>  - [x] tier1 aarch64

Refactoring looks good.

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Marked as reviewed by phh (Reviewer).

PR: https://git.openjdk.org/jdk/pull/12473