[jdk17u-dev] RFR: 8283451: C2: assert(_base == Long) failed: Not a Long

[Martin Doerr]

Clean backport of [JDK-8283451](https://bugs.openjdk.java.net/browse/JDK-8283451)

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Commit messages:
 - Backport fabde3b7b8ed5e576febe8138c14696ccdf636d5

Changes: https://git.openjdk.java.net/jdk17u-dev/pull/313/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17u-dev&pr=313&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8283451
  Stats: 80 lines in 2 files changed: 78 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk17u-dev/pull/313.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17u-dev pull/313/head:pull/313

PR: https://git.openjdk.java.net/jdk17u-dev/pull/313