RFR: 8304743: Compile_lock and SystemDictionary updates

Fri Mar 31 17:54:29 UTC 2023

The SystemDictionary is updated and read under the Compile_lock but this is unnecessary because the table is a concurrent hashtable, and the lock doesn't really synchronize any other compilation state.  The lock may have protected other state that Dependencies used in the past but has been removed.   See discussion in CR for more information.
Tested with tier1-8.

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Commit messages:
 - 8304743: Compile_lock and SystemDictionary updates

Changes: https://git.openjdk.org/jdk/pull/13270/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13270&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8304743
  Stats: 36 lines in 3 files changed: 1 ins; 21 del; 14 mod
  Patch: https://git.openjdk.org/jdk/pull/13270.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13270/head:pull/13270

PR: https://git.openjdk.org/jdk/pull/13270