RFR: 8355667: RISC-V: Add backend implementation for unsigned vector Min / Max operations

[Fei Yang]

Hi, please review this change.
https://bugs.openjdk.org/browse/JDK-8338021 proposed new vector operators including Unsigned Vector Min / Max.
This intrinsify Unsigned Vector Min / Max operations with RVV extension for RISC-V backend to improve performance.
This also enables some extra IR tests in file test/hotspot/jtreg/compiler/vectorapi/VectorCommutativeOperSharingTest.java.

Testing:
- [x] make test TEST="jdk_vector" (QEMU / fastdebug)

JMH tested on BPI-F3 SBC for reference:
Before:

ByteMaxVector.UMAX          1024  thrpt    5  58.657 ± 17.216  ops/ms
ByteMaxVector.UMAXMasked    1024  thrpt    5  45.581 ± 18.164  ops/ms
ByteMaxVector.UMIN          1024  thrpt    5  55.275 ± 15.863  ops/ms
ByteMaxVector.UMINMasked    1024  thrpt    5  44.651 ± 29.209  ops/ms
ShortMaxVector.UMAX          1024  thrpt    5  24.146 ± 7.570  ops/ms
ShortMaxVector.UMAXMasked    1024  thrpt    5  21.506 ± 0.430  ops/ms
ShortMaxVector.UMIN          1024  thrpt    5  24.261 ± 6.993  ops/ms
ShortMaxVector.UMINMasked    1024  thrpt    5  20.980 ± 1.622  ops/ms
IntMaxVector.UMAX          1024  thrpt    5  10.780 ± 0.812  ops/ms
IntMaxVector.UMAXMasked    1024  thrpt    5  10.609 ± 0.851  ops/ms
IntMaxVector.UMIN          1024  thrpt    5  10.845 ± 0.578  ops/ms
IntMaxVector.UMINMasked    1024  thrpt    5  10.705 ± 0.562  ops/ms
LongMaxVector.UMAX          1024  thrpt    5  5.445 ± 0.439  ops/ms
LongMaxVector.UMAXMasked    1024  thrpt    5  5.387 ± 0.285  ops/ms
LongMaxVector.UMIN          1024  thrpt    5  5.379 ± 0.407  ops/ms
LongMaxVector.UMINMasked    1024  thrpt    5  5.373 ± 0.236  ops/ms


After:

ByteMaxVector.UMAX          1024  thrpt    5  2552.161 ±  121.213  ops/ms
ByteMaxVector.UMAXMasked    1024  thrpt    5  2444.001 ±  105.139  ops/ms
ByteMaxVector.UMIN          1024  thrpt    5  2616.963 ±    3.065  ops/ms
ByteMaxVector.UMINMasked    1024  thrpt    5  2367.968 ± 1057.028  ops/ms
ShortMaxVector.UMAX          1024  thrpt    5  1363.676 ±   9.294  ops/ms
ShortMaxVector.UMAXMasked    1024  thrpt    5  1321.759 ± 121.471  ops/ms
ShortMaxVector.UMIN          1024  thrpt    5  1368.598 ±   5.251  ops/ms
ShortMaxVector.UMINMasked    1024  thrpt    5  1337.044 ±   1.434  ops/ms
IntMaxVector.UMAX          1024  thrpt    5  566.509 ±  0.658  ops/ms
IntMaxVector.UMAXMasked    1024  thrpt    5  559.456 ±  0.491  ops/ms
IntMaxVector.UMIN          1024  thrpt    5  569.238 ±  1.309  ops/ms
IntMaxVector.UMINMasked    1024  thrpt    5  535.359 ± 15.765  ops/ms
LongMaxVector.UMAX          1024  thrpt    5  367.765 ±  0.835  ops/ms
LongMaxVector.UMAXMasked    1024  thrpt    5  366.470 ±  1.179  ops/ms
LongMaxVector.UMIN          1024  thrpt    5  365.960 ±  2.007  ops/ms
LongMaxVector.UMINMasked    1024  thrpt    5  268.859 ± 14.090  ops/ms

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

Commit messages:
 - 8355667: RISC-V: Add backend implementation for unsigned vector Min / Max operations

Changes: https://git.openjdk.org/jdk/pull/24909/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24909&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8355667
  Stats: 91 lines in 3 files changed: 56 ins; 0 del; 35 mod
  Patch: https://git.openjdk.org/jdk/pull/24909.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24909/head:pull/24909

PR: https://git.openjdk.org/jdk/pull/24909