RFR: 8349705: java.net.URI.scanIPv4Address throws unnecessary URISyntaxException

[Xiaolong Peng]

java.net.URI.scanIPv4Address is a private method, it is only called by java.net.URI.takeIPv4Address and java.net.URI.parseIPv4Address, the URISyntaxException("Malformed IPv4 address") is not necessary, returning -1 should be good. In one of our systems, we noticed the exception consumes ~0.3% CPU.

Additional test:
- [x] make test TEST=jdk/java/net

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Commit messages:
 - 8349705: java.net.URI.scanIPv4Address throws unnecessary URISyntaxException

Changes: https://git.openjdk.org/jdk/pull/23538/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23538&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8349705
  Stats: 6 lines in 1 file changed: 4 ins; 1 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/23538.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23538/head:pull/23538

PR: https://git.openjdk.org/jdk/pull/23538