[jdk20u] RFR: 8304871: Use default visibility for static library builds

[Severin Gehwolf]

Clean backport for a change to the static library build. Very little risk as it only affects static library consumers (mostly GraalVM and Mandrel). It fixes an issue there for the recent AWT changes done in the upcoming release.

Testing: Manual test using Mandrel & ImageIO (awt). Broken before, fixed after.

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Commit messages:
 - Backport f0dba218ac00c0c577400b4d864ba79a9938aef7

Changes: https://git.openjdk.org/jdk20u/pull/45/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk20u&pr=45&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8304871
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk20u/pull/45.diff
  Fetch: git fetch https://git.openjdk.org/jdk20u.git pull/45/head:pull/45

PR: https://git.openjdk.org/jdk20u/pull/45