[lworld] RFR: 8369921: [lworld] Remove caches of primitive wrapper classes [v3]

[Roger Riggs]

> Disable use of wrapper cached values when --enable-preview and add javadoc descriptions for enable-preview.
> The wrapper classes are Byte, Short, Character, Integer, and Long.

Roger Riggs has updated the pull request incrementally with one additional commit since the last revision:

  One more assignment into the !Preview block in Short.

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Changes:
  - all: https://git.openjdk.org/valhalla/pull/1685/files
  - new: https://git.openjdk.org/valhalla/pull/1685/files/10eab814..7a94a947

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=valhalla&pr=1685&range=02
 - incr: https://webrevs.openjdk.org/?repo=valhalla&pr=1685&range=01-02

  Stats: 2 lines in 1 file changed: 1 ins; 1 del; 0 mod
  Patch: https://git.openjdk.org/valhalla/pull/1685.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1685/head:pull/1685

PR: https://git.openjdk.org/valhalla/pull/1685