[riscv-port-jdk17u:riscv-port] RFR: 8301033: RISC-V: Handle special cases for MinI/MaxI nodes for Zbb

[Dingli Zhang]

Hi, please review this backport to riscv-port-jdk17u.
Backport of [JDK-8301033](https://bugs.openjdk.org/browse/JDK-8301033). Applies cleanly.

The difference in -XX:+PrintOptoAssembly output looks like:
Before:

048 li R7, #0 # int, #@loadConI
04a + max R10, R12, R7 #@maxI_reg_b
04e # pop frame 32


After:

048 max R10, R12, zr #@maxI_reg_zero_b
04c # pop frame 32


Before:

028 li R7, #0 # int, #@loadConI
02a + min R10, R11, R7 #@minI_reg_b
02e # pop frame 32


After:

028 min R10, R11, zr #@minI_reg_zero_b
02c # pop frame 32


Testing:
- https://github.com/openjdk/jdk/blob/master/test/hotspot/jtreg/compiler/intrinsics/math/TestMinMaxIntrinsics.java
- tier1-3 tests on QEMU-System w/ and w/o UseZbb (release build)
- tier1-3 tests on unmatched board w/o UseZbb (release build)

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

Commit messages:
 - 8301033: RISC-V: Handle special cases for MinI/MaxI nodes for Zbb

Changes: https://git.openjdk.org/riscv-port-jdk17u/pull/66/files
 Webrev: https://webrevs.openjdk.org/?repo=riscv-port-jdk17u&pr=66&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8301033
  Stats: 38 lines in 1 file changed: 34 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/riscv-port-jdk17u/pull/66.diff
  Fetch: git fetch https://git.openjdk.org/riscv-port-jdk17u.git pull/66/head:pull/66

PR: https://git.openjdk.org/riscv-port-jdk17u/pull/66