[lworld] RFR: 8244339: [lworld] JIT support for inline types with abstract class supertypes

[Tobias Hartmann]

C1 and C2 do not correctly handle and optimize inline types with abstract class supertypes and corresponding array
covariance. I've fixed and refactored related code. Added lots of tests and IR verification of optimizations.

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Commit messages:
 - 8244339: [lworld] JIT support for inline types with abstract class supertypes

Changes: https://git.openjdk.java.net/valhalla/pull/33/files
 Webrev: https://webrevs.openjdk.java.net/valhalla/33/webrev.00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8244339
  Stats: 1011 lines in 17 files changed: 917 ins; 15 del; 79 mod
  Patch: https://git.openjdk.java.net/valhalla/pull/33.diff
  Fetch: git fetch https://git.openjdk.java.net/valhalla pull/33/head:pull/33

PR: https://git.openjdk.java.net/valhalla/pull/33