[lworld] RFR: 8280382: [lworld] JCWithField AST node support should evolve to work with value classes

[Aggelos Biboudis]

This PR ports basic `withField` tests from lworld-values to value-objects and extending some areas of code to support `withField` within value classes.

Nitpicking and a note: one of the error messages is now `compiler.err.primitive.or.value.class.instance.field.expected.here`. Would you propose to disambiguate further depending whether we are inside a `primitive` or a `value` class?

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Commit messages:
 - 8280382: [lworld] JCWithField AST node support should evolve to work with value classes

Changes: https://git.openjdk.java.net/valhalla/pull/621/files
 Webrev: https://webrevs.openjdk.java.net/?repo=valhalla&pr=621&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8280382
  Stats: 601 lines in 19 files changed: 586 ins; 0 del; 15 mod
  Patch: https://git.openjdk.java.net/valhalla/pull/621.diff
  Fetch: git fetch https://git.openjdk.java.net/valhalla pull/621/head:pull/621

PR: https://git.openjdk.java.net/valhalla/pull/621