RFR: 8297238: RISC-V: Fix another two C2 IR matching tests for RISC-V

[Gui Cao]

Fix two IR matching tests that failed on RISC-V.

Vector api Node will be matched only when UseRVV is enabled:
- test/hotspot/jtreg/compiler/c2/irTests/TestAutoVectorization2DArray.java
- test/hotspot/jtreg/compiler/vectorization/TestAutoVecIntMinMax.java

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

## Testing:
-  test/hotspot/jtreg/compiler/c2/irTests/TestAutoVectorization2DArray.java - no tests selected as expected (on unmatched board)
-  test/hotspot/jtreg/compiler/vectorization/TestAutoVecIntMinMax.java - no tests selected as expected (on unmatched board)

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Commit messages:
 - RISC-V: Fix another two C2 IR matching tests for RISC-V

Changes: https://git.openjdk.org/jdk/pull/11577/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11577&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8297238
  Stats: 5 lines in 3 files changed: 3 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/11577.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11577/head:pull/11577

PR: https://git.openjdk.org/jdk/pull/11577