RFR: 8220: Make LocalJVMToolkit reflective [v2]

[Marcus Hirt]

> Less painful from within Eclipse.

Marcus Hirt has updated the pull request incrementally with one additional commit since the last revision:

  Error message and null check

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Changes:
  - all: https://git.openjdk.org/jmc/pull/563/files
  - new: https://git.openjdk.org/jmc/pull/563/files/5f1b51b5..10f2a532

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jmc&pr=563&range=01
 - incr: https://webrevs.openjdk.org/?repo=jmc&pr=563&range=00-01

  Stats: 8 lines in 2 files changed: 3 ins; 0 del; 5 mod
  Patch: https://git.openjdk.org/jmc/pull/563.diff
  Fetch: git fetch https://git.openjdk.org/jmc.git pull/563/head:pull/563

PR: https://git.openjdk.org/jmc/pull/563