Poor performance when parsing huge literal in query (e.g. 100MB)

The cause seems to be https://github.com/javacc/javacc/issues/72

We encountered this issue when a SPARQL SERVICE clause was sending a large-ish Geometry literal of USA to Fuseki. It stalls forever trying to parse the query.

Ideally, the buffer would expand exponentially or there is an alternative PR linked in the javacc issue. Currently, the parsing buffer is apparently grown in steps of 2KiB

jstack:

```
"qtp771666241-136" #136 prio=5 os_prio=0 cpu=13385,35ms elapsed=5538,68s tid=0x00007fa188007800 nid=0x15730d runnable [0x00007fa1341f9000]
java.lang.Thread.State: RUNNABLE
at org.apache.jena.sparql.lang.arq.SimpleCharStream.ExpandBuff(SimpleCharStream.java:42)
at org.apache.jena.sparql.lang.arq.SimpleCharStream.FillBuff(SimpleCharStream.java:103)
at org.apache.jena.sparql.lang.arq.SimpleCharStream.readChar(SimpleCharStream.java:197)
at org.apache.jena.sparql.lang.arq.ARQParserTokenManager.jjMoveNfa_0(ARQParserTokenManager.java:4369)
at org.apache.jena.sparql.lang.arq.ARQParserTokenManager.jjMoveStringLiteralDfa0_0(ARQParserTokenManager.java:211)
at org.apache.jena.sparql.lang.arq.ARQParserTokenManager.getNextToken(ARQParserTokenManager.java:4793)
at org.apache.jena.sparql.lang.arq.ARQParser.jj_ntk_f(ARQParser.java:8162)
at org.apache.jena.sparql.lang.arq.ARQParser.PathElt(ARQParser.java:3603)
at org.apache.jena.sparql.lang.arq.ARQParser.PathEltOrInverse(ARQParser.java:3635)
at org.apache.jena.sparql.lang.arq.ARQParser.PathSequence(ARQParser.java:3565)
at org.apache.jena.sparql.lang.arq.ARQParser.PathAlternative(ARQParser.java:3544)
at org.apache.jena.sparql.lang.arq.ARQParser.Path(ARQParser.java:3538)
at org.apache.jena.sparql.lang.arq.ARQParser.VerbPath(ARQParser.java:3493)
at org.apache.jena.sparql.lang.arq.ARQParser.PropertyListPathNotEmpty(ARQParser.java:3418)
at org.apache.jena.sparql.lang.arq.ARQParser.TriplesSameSubjectPath(ARQParser.java:3365)
at org.apache.jena.sparql.lang.arq.ARQParser.TriplesBlock(ARQParser.java:2512)
at org.apache.jena.sparql.lang.arq.ARQParser.GroupGraphPatternSub(ARQParser.java:2425)
at org.apache.jena.sparql.lang.arq.ARQParser.GroupGraphPattern(ARQParser.java:2387)
at org.apache.jena.sparql.lang.arq.ARQParser.WhereClause(ARQParser.java:858)
at org.apache.jena.sparql.lang.arq.ARQParser.SelectQuery(ARQParser.java:137)
at org.apache.jena.sparql.lang.arq.ARQParser.Query(ARQParser.java:31)
at org.apache.jena.sparql.lang.arq.ARQParser.QueryUnit(ARQParser.java:22)
at org.apache.jena.sparql.lang.ParserARQ$1.exec(ParserARQ.java:48)
at org.apache.jena.sparql.lang.ParserARQ.perform(ParserARQ.java:95)
at org.apache.jena.sparql.lang.ParserARQ.parse$(ParserARQ.java:52)
at org.apache.jena.sparql.lang.SPARQLParser.parse(SPARQLParser.java:33)
at org.apache.jena.query.QueryFactory.parse(QueryFactory.java:144)
at org.apache.jena.query.QueryFactory.create(QueryFactory.java:83)
at org.apache.jena.fuseki.servlets.SPARQLQueryProcessor.execute(SPARQLQueryProcessor.java:251)
at org.apache.jena.fuseki.servlets.SPARQLQueryProcessor.executeBody(SPARQLQueryProcessor.java:234)
at org.apache.jena.fuseki.servlets.SPARQLQueryProcessor.execute(SPARQLQueryProcessor.java:213)
at org.apache.jena.fuseki.servlets.ActionService.executeLifecycle(ActionService.java:58)
at org.apache.jena.fuseki.servlets.SPARQLQueryProcessor.execPost(SPARQLQueryProcessor.java:83)
at org.apache.jena.fuseki.servlets.ActionProcessor.process(ActionProcessor.java:34)
at org.apache.jena.fuseki.servlets.ActionBase.process(ActionBase.java:55)
at org.apache.jena.fuseki.servlets.ActionExecLib.execActionSub(ActionExecLib.java:125)
at org.apache.jena.fuseki.servlets.ActionExecLib.execAction(ActionExecLib.java:99)
at org.apache.jena.fuseki.server.Dispatcher.dispatchAction(Dispatcher.java:164)
at org.apache.jena.fuseki.server.Dispatcher.process(Dispatcher.java:156)
at org.apache.jena.fuseki.server.Dispatcher.dispatch(Dispatcher.java:83)
at org.apache.jena.fuseki.servlets.FusekiFilter.doFilter(FusekiFilter.java:48)
at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:202)
at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1600)
at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:61)
at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:450)
at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365)
at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90)
at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83)
at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:387)
at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362)
at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:202)
at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1600)
at org.apache.jena.fuseki.servlets.CrossOriginFilter.handle(CrossOriginFilter.java:284)
at org.apache.jena.fuseki.servlets.CrossOriginFilter.doFilter(CrossOriginFilter.java:247)
at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:210)
at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1600)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:506)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:131)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:578)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:122)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:223)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1571)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:221)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1378)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:176)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:463)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1544)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:174)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1300)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:129)
at org.eclipse.jetty.server.handler.gzip.GzipHandler.handle(GzipHandler.java:717)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:122)
at org.eclipse.jetty.server.Server.handle(Server.java:562)
at org.eclipse.jetty.server.HttpChannel.lambda$handle$0(HttpChannel.java:505)
at org.eclipse.jetty.server.HttpChannel$$Lambda$636/0x000000084084d040.dispatch(Unknown Source)
at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:762)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:497)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:282)
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:319)
at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:100)
at org.eclipse.jetty.io.SelectableChannelEndPoint$1.run(SelectableChannelEndPoint.java:53)
at org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.runTask(AdaptiveExecutionStrategy.java:412)
at org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.consumeTask(AdaptiveExecutionStrategy.java:381)
at org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.tryProduce(AdaptiveExecutionStrategy.java:268)
at org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy.lambda$new$0(AdaptiveExecutionStrategy.java:138)
at org.eclipse.jetty.util.thread.strategy.AdaptiveExecutionStrategy$$Lambda$624/0x0000000840830c40.run(Unknown Source)
at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:407)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:894)
at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1038)
at java.lang.Thread.run(java.base@11.0.15/Thread.java:829)
```

query is something simple as
```
{ ?c ^ "HUGE POS LIST"^^ }
```

automatically injected from a service clause

Start with the generated org.apache.jena.sparql.lang.arq.SimpleCharStream.java, especially ExpandBuff, FillBuff, and readChar, then trace how ARQParserTokenManager consumes a large literal. Reproduce the issue with the shown SPARQL query and a very large POS list; done means parsing no longer stalls and the large-literal case completes successfully.

Written by the indexing model from the issue text.