RFR: 8291027: Some of TimeZone methods marked 'synchronized' unnecessarily [v2]

[Andrey Turbanov]

> There are 3 methods in `java.util.TimeZone` which are `public static` and marked as `synchronized`:
> 1. getTimeZone(String)
> 2. getAvailableIDs(int)
> 3. getAvailableIDs()
> 
> This means it is a bottle neck for the whole VM.
> I've checked the implementation and concluded that `synchronized` is unnecessary.

Andrey Turbanov has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains two commits:

 - Merge remote-tracking branch 'refs/remotes/origin/master' into JDK-8291027-TimeZone-synchronized
   
   # Conflicts:
   #	src/java.base/share/classes/java/util/TimeZone.java
 - 8291027: Some of TimeZone methods marked 'synchronized' unnecessarily

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

Changes: https://git.openjdk.org/jdk/pull/17441/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17441&range=01
  Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/17441.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17441/head:pull/17441

PR: https://git.openjdk.org/jdk/pull/17441