RFR: 8296515: RISC-V: Optimized MaxReductionV/MinReductionV/AddReductionV node implementation

[Gui Cao]

HI,

The MaxReductionV, MinReductionV, AddReductionV nodes currently implemented by riscv rvv can be implemented by calling shared functions, and the T_BYTE and T_SHORT types in the MaxReductionV and MinReductionV node implementations can also be implemented in the same way as the T_INT type.

Please take a look and have some reviews. Thanks a lot.

## Testing:
- hotspot and jdk tier1 on unmatched board without new failures
- test/jdk/jdk/incubator/vector/* with fastdebug on qemu

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

Commit messages:
 - Optimized MaxReductionV/MinReductionV/AddReductionV node implementation

Changes: https://git.openjdk.org/jdk/pull/11036/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11036&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8296515
  Stats: 173 lines in 4 files changed: 14 ins; 114 del; 45 mod
  Patch: https://git.openjdk.org/jdk/pull/11036.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11036/head:pull/11036

PR: https://git.openjdk.org/jdk/pull/11036