RFR: 8351839: RISC-V: Fix base offset calculation introduced in JDK-8347489

[Hamlin Li]

On Wed, 12 Mar 2025 11:24:23 GMT, Fei Yang <fyang at openjdk.org> wrote:

> As discussed in https://github.com/openjdk/jdk/pull/23633#discussion_r1974591975, there is no need to distinuish `T_BYTE` and `T_CHAR` when calculating base offset for strings.
> The reason is that the low-level character storage used for both Latin1 and UTF16 strings is always a byte array [1].
> So we should always use `T_BYTE` for both cases. This won't make a difference on the calculated base offset for now.
> But it's better to fix this for code readability purposes. Sanity tested on linux-riscv64 w/wo COH.
> 
> [1] https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java/lang/String.java#L160

Looks good.

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Marked as reviewed by mli (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/24006#pullrequestreview-2678568197