RFR: 8286847: Rotate vectors don't support byte or short [v2]

[Haomin]

> static void test_fun(byte[] a0, int[] b0, byte[] c0) {
>     for (int i=0; i<ARRLEN; i++) {
>       c0[i] = (byte)(a0[i] << (7) | a0[i] >>> (-7));
>     }   
>   }
> 
> 
> when I implement RotateLeftV in loongarch.ad, I found this executed by c2 vector and executed by interpreter are not equal.
> 
> It's executed on x86 would create an assert error.
> 
> 
>  # Internal Error (/home/wanghaomin/jdk/src/hotspot/share/opto/vectornode.cpp:347), pid=26469, tid=26485
>  # assert(false) failed: not supported: byte
> 
> 
> RotateLeftV for byte, short values produces incorrect Java result. Because java code should convert a byte, short value into int value, and then do RotateI.

Haomin has updated the pull request incrementally with one additional commit since the last revision:

  modify testcase

-------------

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8740/files
  - new: https://git.openjdk.java.net/jdk/pull/8740/files/2a01af4a..05ebce18

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8740&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8740&range=00-01

  Stats: 123 lines in 2 files changed: 36 ins; 38 del; 49 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8740.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8740/head:pull/8740

PR: https://git.openjdk.java.net/jdk/pull/8740