RFR: 8295184: Printing messages with a RecordComponentElement does not include position

[Srikanth Adayapalam]

Stash away a copy of the record component declaration from the header for use in diagnostics

-------------

Commit messages:
 - 8295184: Printing messages with a RecordComponentElement does not include position

Changes: https://git.openjdk.org/jdk/pull/11511/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11511&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8295184
  Stats: 225 lines in 7 files changed: 209 ins; 4 del; 12 mod
  Patch: https://git.openjdk.org/jdk/pull/11511.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11511/head:pull/11511

PR: https://git.openjdk.org/jdk/pull/11511