[lworld] RFR: [lworld] clean up VarHandle support for inline type

[Mandy Chung]

`InlineAccessor` and `StaticInlineAccessor` are no longer needed because `Class::cast` will ensure the given object is
non-null if it's an inline object.

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Commit messages:
 - Merge branch 'lworld' of https://github.com/openjdk/valhalla into lw3-fixes
 - Merge branch 'lworld' of https://github.com/openjdk/valhalla into lw3-fixes
 - Merge branch 'lworld' of https://github.com/openjdk/valhalla into lw3-fixes
 - clean up
 - Merge
 - check if both arguments are null
 - Merge
 - [lworld] ValueBootstrapMethods::isSubstitutable0 should do null check and type check
 - Merge
 - Merge
 - ... and 2 more: https://git.openjdk.java.net/valhalla/compare/59d8f6b4...99b7c201

Changes: https://git.openjdk.java.net/valhalla/pull/140/files
 Webrev: https://webrevs.openjdk.java.net/valhalla/140/webrev.00
  Stats: 48 lines in 1 file changed: 0 ins; 46 del; 2 mod
  Patch: https://git.openjdk.java.net/valhalla/pull/140.diff
  Fetch: git fetch https://git.openjdk.java.net/valhalla pull/140/head:pull/140

PR: https://git.openjdk.java.net/valhalla/pull/140