RFR: 8362838: RISC-V: Incorrect matching rule leading to improper oop instruction encoding

[Feilong Jiang]

Same as [JDK-8361892](https://bugs.openjdk.org/browse/JDK-8361892), but for riscv.

Testing:
- [x] Tier1-3 & hotspot:tier4 on linux-riscv64

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Commit messages:
 - RISC-V: Incorrect matching rule leading to improper oop instruction encoding

Changes: https://git.openjdk.org/jdk/pull/26318/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=26318&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8362838
  Stats: 31 lines in 1 file changed: 0 ins; 31 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/26318.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26318/head:pull/26318

PR: https://git.openjdk.org/jdk/pull/26318