[jdk17u] RFR: 8271203: C2: assert(iff->Opcode() == Op_If || iff->Opcode() == Op_CountedLoopEnd || iff->Opcode() == Op_RangeCheck) failed: Check this code when new subtype is added

[Tobias Hartmann]

Backport of [JDK-8271203](https://bugs.openjdk.java.net/browse/JDK-8271203). Applies cleanly.

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Commit messages:
 - 8271203: C2: assert(iff->Opcode() == Op_If || iff->Opcode() == Op_CountedLoopEnd || iff->Opcode() == Op_RangeCheck) failed: Check this code when new subtype is added

Changes: https://git.openjdk.java.net/jdk17u/pull/20/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17u&pr=20&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8271203
  Stats: 66 lines in 2 files changed: 64 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk17u/pull/20.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17u pull/20/head:pull/20

PR: https://git.openjdk.java.net/jdk17u/pull/20