[jdk19u] RFR: 8296771: RISC-V: C2: assert(false) failed: bad AD file

[Xiaolin Zheng]

This is a fix for a fast debug build assertion failure, and the impact is small.
Clean backport from 20.

Testing currently.

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Commit messages:
 - 8296771: RISC-V: C2: assert(false) failed: bad AD file

Changes: https://git.openjdk.org/jdk19u/pull/79/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk19u&pr=79&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8296771
  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk19u/pull/79.diff
  Fetch: git fetch https://git.openjdk.org/jdk19u pull/79/head:pull/79

PR: https://git.openjdk.org/jdk19u/pull/79