Speed up AntPathMatcher by doing prefix-match

[soldierkam]

Many ant style patterns has prefix that can be used to determine if there is no need to do complicated and costly matching.
For example pattern "/static/css/*" have prefix "/static/css/" that can be used to say that path "/api/resource/1234" will not match.

This was tested with https://gist.github.com/soldierkam/c80e433aa9fbec35df5a
Before:

Benchmark	Mode	Cnt	Score	Error	Units
MyBenchmark.isMatching	thrpt	5	425995,288 ±	162966,573	ops/s
MyBenchmark.isNotMatching	thrpt	5	864690,507 ±	130643,210	ops/s
MyBenchmark.suffix	thrpt	5	748551,270 ±	17229,496	ops/s

After:

Benchmark	Mode	Cnt	Score	Error	Units
MyBenchmark.isMatching	thrpt	5	483815,001 ±	105669,816	ops/s
MyBenchmark.isNotMatching	thrpt	5	10208718,438 ±	125879,376	ops/s
MyBenchmark.suffix	thrpt	5	624841,454 ±	349001,674	ops/s

Result: over 10x faster for isNotMatching and 17% slower for "suffix" case.

I tested it with https://github.com/spring-projects/spring-boot/tree/master/spring-boot-samples/spring-boot-sample-data-rest (wrk -c 40 -d 30 -t 2 http://127.0.0.1:8080/api/hotels) but results are almost the same (before: 310.15req/seq, after: 305.41req/sec).
For https://github.com/spring-projects/spring-boot/tree/master/spring-boot-samples/spring-boot-sample-actuator-ui (wrk -c 40 -d 30 -t 2 http://localhost:8080/css/bootstrap.min.css) there is small perf improvement - before: 2237.90req/seq, after: 2353.93req/sec
For real world application (that contains many more endpoints) I've got 17% more throughput for endpoint serving static resource (baseline is at 1812req/sec).

Let me know what you think.

[bclozel]

Thanks @soldierkam for this PR! I'd be happy to review more if you've got other ideas 👍

Indeed, I ran a few JMH benchmarks myself and found that this leads to a consistent performance boost for many cases. AntPathMatcher is a central piece of our infrastructure, so I'm not keen on backporting this change to the latest version of the 4.2.x line. This will be shortly available as a 4.3.0-BUILD-SNAPSHOT version.

Merged as e77ff3c for SPR-13913