RFR: 8349632: RISC-V: Add Zfa fminm/fmaxm [v2]

[Anjian Wen]

> Add RISCV zfa extension fminm/fmaxm
> This two new Floating-point instructions can deal with NaN input directly, which can decrease instructions when calculate min or max

Anjian Wen has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains six additional commits since the last revision:

 - Merge branch 'openjdk:master' into Zfa_dev_branch
 - 8349632: RISC-V: Add Zfa fminm/fmaxm
   
   Change macro-assembler routine to directly call in riscv.ad
 - JDK-8349632: RISC-V: Add Zfa fminm/fmaxm
   
   add zfa predicate
 - 8349632: RISC-V: Add Zfa fminm/fmaxm
   
   delete assert in new add macroAssembly but not the old
 - JDK-8349632: RISCV: Add Zfa fminm/fmaxm
   
   delete assert and change fminm/fmaxm to new match rule
 - 8349632:RISC-V: Add Zfa fminm/fmaxm

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/23509/files
  - new: https://git.openjdk.org/jdk/pull/23509/files/b763ee4d..927d0244

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23509&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23509&range=00-01

  Stats: 102279 lines in 2523 files changed: 51917 ins; 33646 del; 16716 mod
  Patch: https://git.openjdk.org/jdk/pull/23509.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23509/head:pull/23509

PR: https://git.openjdk.org/jdk/pull/23509