[riscv-port-jdk17u:riscv-port] RFR: 8296975: RISC-V: Enable UseRVA20U64 profile by default

[Fei Yang]

On Mon, 3 Apr 2023 03:41:56 GMT, Xiaolin Zheng <xlinzheng at openjdk.org> wrote:

> The last backported patch of RVC - to enable it by default.
> 
> Although, we don't have `UseRVA20U64` in jdk17, so I only made `UseRVC` true here. Looking forward to some opinions about it.
> 
> Tested hotspot tier1~4 with fastdebug build.

Looks OK.

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Marked as reviewed by fyang (Committer).

PR Review: https://git.openjdk.org/riscv-port-jdk17u/pull/33#pullrequestreview-1368264263