CLDR-17014 Change HashMap to ConcurrentHashMap in ExtraPaths

[btangmu]

-ConcurrentModificationException was thrown when ExtraPaths.getInstance called computeIfAbsent during cldr-generate-json.sh

-Unable to repro the exception before making this change

CLDR-17014

• This PR completes the ticket.

ALLOW_MANY_COMMITS=true

[btangmu]

Compare older alternative #4317 which adds synchronized

[btangmu]

This fails ConsoleCheckCLDR:

 Caused by: java.util.ConcurrentModificationException
	at java.base/java.util.HashMap$HashIterator.nextNode(HashMap.java:1511)
	at java.base/java.util.HashMap$KeyIterator.next(HashMap.java:1534)
	at java.base/java.util.AbstractCollection.addAll(AbstractCollection.java:351)
	at org.unicode.cldr.util.ExtraPaths.append(ExtraPaths.java:31)
	at org.unicode.cldr.util.CLDRFile.getRawExtraPathsPrivate(CLDRFile.java:3156)
	at org.unicode.cldr.util.CLDRFile.getRawExtraPaths(CLDRFile.java:3122)
	at org.unicode.cldr.util.CLDRFile.getExtraPaths(CLDRFile.java:3087)
	at org.unicode.cldr.util.CLDRFile$FullIterable.next(CLDRFile.java:1518)
	at org.unicode.cldr.util.CLDRFile$FullIterable.next(CLDRFile.java:1497)
	at org.unicode.cldr.util.With$ToIterator.next(With.java:383)
	at org.unicode.cldr.test.ConsoleCheckCLDR.lambda$main$0(ConsoleCheckCLDR.java:659)

[btangmu]

@macchiati @srl295 tests passed locally but ConsoleCheckCLDR fails here, so maybe we need synchronized (#4317) after all or some other solution

[btangmu]

I don't often run ConsoleCheckCLDR locally, and didn't run it before making this PR. Running it locally now, I do get ConcurrentModificationException:

$ java -DCLDR_DIR=$(pwd) -jar tools/cldr-code/target/cldr-code.jar check -S common,seed -e -z FINAL_TESTING
>> org.unicode.cldr.test.ConsoleCheckCLDR
[-S, common,seed, -e, -z, FINAL_TESTING]
#-f	file_filter	≝	.*
#-t	test_filter	≝	.*
#-o	organization	≝	.*
...
# fr_MU [French (Mauritius)]	Summary	modern	Items:	14586	Raw Missing:	14585	Raw Provisional:	0
# fr_MU Elapsed time: : 655.2 ms
Exception in thread "main" java.lang.reflect.InvocationTargetException
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.unicode.cldr.tool.Main.invoke(Main.java:60)
	at org.unicode.cldr.tool.Main.main(Main.java:47)
Caused by: java.util.ConcurrentModificationException: java.util.ConcurrentModificationException
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:490)
	at java.base/java.util.concurrent.ForkJoinTask.getThrowableException(ForkJoinTask.java:600)
	at java.base/java.util.concurrent.ForkJoinTask.reportException(ForkJoinTask.java:678)
	at java.base/java.util.concurrent.ForkJoinTask.invoke(ForkJoinTask.java:737)
	at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateParallel(ForEachOps.java:159)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateParallel(ForEachOps.java:173)
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:233)
	at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
	at java.base/java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:661)
	at org.unicode.cldr.test.ConsoleCheckCLDR.main(ConsoleCheckCLDR.java:543)
	... 6 more
Caused by: java.util.ConcurrentModificationException
	at java.base/java.util.HashMap$HashIterator.nextNode(HashMap.java:1511)
	at java.base/java.util.HashMap$KeyIterator.next(HashMap.java:1534)
	at java.base/java.util.AbstractCollection.addAll(AbstractCollection.java:351)
	at org.unicode.cldr.util.ExtraPaths.append(ExtraPaths.java:31)
	at org.unicode.cldr.util.CLDRFile.getRawExtraPathsPrivate(CLDRFile.java:3157)
	at org.unicode.cldr.util.CLDRFile.getRawExtraPaths(CLDRFile.java:3122)
	at org.unicode.cldr.util.CLDRFile.getExtraPaths(CLDRFile.java:3087)
	at org.unicode.cldr.util.CLDRFile$FullIterable.next(CLDRFile.java:1518)
	at org.unicode.cldr.util.CLDRFile$FullIterable.next(CLDRFile.java:1497)
	at org.unicode.cldr.util.With$ToIterator.next(With.java:383)
	at org.unicode.cldr.test.ConsoleCheckCLDR.lambda$main$0(ConsoleCheckCLDR.java:659)
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
	at java.base/java.util.TreeMap$KeySpliterator.forEachRemaining(TreeMap.java:2739)
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
	at java.base/java.util.stream.ForEachOps$ForEachTask.compute(ForEachOps.java:290)
	at java.base/java.util.concurrent.CountedCompleter.exec(CountedCompleter.java:746)
	at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:290)
	at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1020)
	at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1656)
	at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1594)
	at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:183)

[macchiati]

see ticket