RFR: JDK-8314272: Improve java.util.prefs.BackingStoreException: Couldn't get file lock. [v2]

[Matthias Baesken]

> We run into some BackingStoreException: Couldn't get file lock. e.g. here :
> 
> [JShell] Exception in thread "main" java.lang.IllegalStateException: java.util.prefs.BackingStoreException: Couldn't get file lock.
> [JShell] at jdk.jshell/jdk.internal.jshell.tool.JShellToolBuilder$PreferencesStorage.flush(JShellToolBuilder.java:313)
> [JShell] at jdk.jshell/jdk.internal.jshell.tool.JShellTool$ReplayableHistory.storeHistory(JShellTool.java:692)
> [JShell] at jdk.jshell/jdk.internal.jshell.tool.JShellTool.start(JShellTool.java:1008)
> [JShell] at jdk.jshell/jdk.internal.jshell.tool.JShellToolBuilder.start(JShellToolBuilder.java:261)
> [JShell] at jdk.jshell/jdk.internal.jshell.tool.JShellToolProvider.main(JShellToolProvider.java:120)
> [JShell] Caused by: java.util.prefs.BackingStoreException: Couldn't get file lock.
> [JShell] at java.prefs/java.util.prefs.FileSystemPreferences.sync(FileSystemPreferences.java:769)
> [JShell] at java.prefs/java.util.prefs.FileSystemPreferences.flush(FileSystemPreferences.java:864)
> [JShell] at jdk.jshell/jdk.internal.jshell.tool.JShellToolBuilder$PreferencesStorage.flush(JShellToolBuilder.java:311)
> [JShell] ... 4 more
> 
> The BackingStoreException should be enhanced e.g. by adding the errno/errorCode that is already available in the coding

Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:

  add for some errnos also the string

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/15308/files
  - new: https://git.openjdk.org/jdk/pull/15308/files/49519782..9230e1e3

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15308&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15308&range=00-01

  Stats: 32 lines in 1 file changed: 26 ins; 0 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/15308.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15308/head:pull/15308

PR: https://git.openjdk.org/jdk/pull/15308