[riscv-port] RFR: 8278994: riscv: RVC support [v19]

[Fei Yang]

On Mon, 17 Jan 2022 12:30:43 GMT, Xiaolin Zheng <xlinzheng at openjdk.org> wrote:

>> Hi team,
>> 
>> This patch includes the basic definition of the RVC instruction set and some cleanups. Tested a simple `test/hotspot/jtreg/compiler/` folder on qemu.
>> 
>> Using `<JAVA_HOME>/bin/java -XX:+UnlockExperimentalVMOptions -XX:+UseRVC -XX:+UnlockDiagnosticVMOptions -XX:+PrintAssembly -XX:PrintAssemblyOptions=no-aliases,numeric -XX:+PrintStubCode -XX:-TieredCompilation` could show RVC instructions.
>> 
>> Thanks,
>> Xiaolin
>
> Xiaolin Zheng has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Polish English comments as suggestions

Approved. Thanks.

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Marked as reviewed by fyang (Lead).

PR: https://git.openjdk.java.net/riscv-port/pull/34