RFR: 8339359: RISC-V: Use auipc explicitly in far_jump and far_call macro assembler routines

[Ludovic Henry]

On Mon, 2 Sep 2024 01:15:36 GMT, Fei Yang <fyang at openjdk.org> wrote:

> Previous discussion: https://github.com/openjdk/jdk/pull/18942#issuecomment-2109162337
> 
> For MacroAssembler::far_call and MacroAssembler::far_jump, I would suggest we use explicit
> auipc instead of MacroAssembler::la for them as the destination is ensured to be in code cache.
> This will help save unnecessary check in MacroAssembler::la and make the code more consistent.
> Also this will help distinguish these two macro assembler routines from MacroAssembler::rt_call
> 
> Testing:
> - [x] release & fastdebug builds
> - [ ] Tiered 1-3 tests

LGTM

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Marked as reviewed by luhenry (Committer).

PR Review: https://git.openjdk.org/jdk/pull/20805#pullrequestreview-2275682328