RFR: 8331285: Deprecate and obsolete OldSize

[Albert Mingkun Yang]

Simple deprecating a jvm flag.

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

Commit messages:
 - old-size

Changes: https://git.openjdk.org/jdk/pull/18994/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18994&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8331285
  Stats: 2 lines in 2 files changed: 1 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/18994.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18994/head:pull/18994

PR: https://git.openjdk.org/jdk/pull/18994