RFR: 8254: Allow primitive types in converters

[Ralf Schmelter]

This allows primitive types in converters.

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Commit messages:
 - Merge branch 'master' of https://github.com/openjdk/jmc into allow_primitives_in_converters
 - Update copyright
 - Allow converters form primitive input types too

Changes: https://git.openjdk.org/jmc/pull/584/files
  Webrev: https://webrevs.openjdk.org/?repo=jmc&pr=584&range=00
  Issue: https://bugs.openjdk.org/browse/JMC-8254
  Stats: 292 lines in 4 files changed: 285 ins; 0 del; 7 mod
  Patch: https://git.openjdk.org/jmc/pull/584.diff
  Fetch: git fetch https://git.openjdk.org/jmc.git pull/584/head:pull/584

PR: https://git.openjdk.org/jmc/pull/584