[lworld] RFR: 8336782: [lworld] CallStaticJavaNode::remove_useless_allocation does not handle dying subgraph

[Tobias Hartmann]

We assert when processing the `load_unknown_inline` call of a flat array load with unknown type because the call already has top as control input. This can happen when a subgraph is dying but depending on the IGVN worklist order, we visit one of the to-be-removed nodes before that. Unfortunately, I was not able to extract a simple test. The fix is to return when encountering a top input.

I also fixed a few outdated comments and did some minor refactoring.

Best regards,
Tobias

-------------

Commit messages:
 - Renaming
 - 8336782: [lworld] CallStaticJavaNode::remove_useless_allocation does not handle dying subgraph

Changes: https://git.openjdk.org/valhalla/pull/1209/files
  Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1209&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8336782
  Stats: 30 lines in 2 files changed: 2 ins; 4 del; 24 mod
  Patch: https://git.openjdk.org/valhalla/pull/1209.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1209/head:pull/1209

PR: https://git.openjdk.org/valhalla/pull/1209