[lworld] RFR: 8281325: [lworld] Unused code emitted for unpacking arguments leads to code buffer overflow

[Tobias Hartmann]

An unrelated change to javac that came in with the mainline merge triggered this:
When emitting code to scalarize a buffered inline type argument in the method entries, there is sometimes an overlap with registers/stack slots occupied by another argument that needs to be resolved before we can make progress. We should not emit any code in such a case and proceed with the next argument (we will revisit this argument later, once the conflict has been resolved).

Some of that code will be refactored by [JDK-8278390](https://bugs.openjdk.java.net/browse/JDK-8278390) anyway.

Thanks,
Tobias

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Commit messages:
 - Typo
 - Removed from problem list
 - 8281325: [lworld] Unused code emitted for unpacking arguments leads to code buffer overflow

Changes: https://git.openjdk.java.net/valhalla/pull/633/files
 Webrev: https://webrevs.openjdk.java.net/?repo=valhalla&pr=633&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8281325
  Stats: 64 lines in 3 files changed: 31 ins; 20 del; 13 mod
  Patch: https://git.openjdk.java.net/valhalla/pull/633.diff
  Fetch: git fetch https://git.openjdk.java.net/valhalla pull/633/head:pull/633

PR: https://git.openjdk.java.net/valhalla/pull/633