RFR: JDK-8322218: Better escaping of single and double quotes in annotation toString() results

[Joe Darcy]

A double quote character doesn't need to be escaped when it is a char literal and single quote character doesn't need to be escaped when it is in a string. This change updates the toString() output of annotations to account for the different escaping requirements of strings and characters.

Corresponding issue filed for javac's compile-time annotations: JDK-8325078.

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Commit messages:
 - JDK-8322218: Better quoting of single and double quotes in annotation toString() results

Changes: https://git.openjdk.org/jdk/pull/17664/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17664&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8322218
  Stats: 18 lines in 2 files changed: 6 ins; 0 del; 12 mod
  Patch: https://git.openjdk.org/jdk/pull/17664.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17664/head:pull/17664

PR: https://git.openjdk.org/jdk/pull/17664