RFR: 8333427: langtools/tools/javac/newlines/NewLineTest.java is failing on Japanese Windows

[KIRIYAMA Takuya]

I fixed to get Charset from native.encoding instead of Charset.defaultCharset() when reading a file to which the output of javac run in the test was redirected.
The modified code is based on the alternatives given in JEP400.
I verified that the test passed on Windows in both Japanese and English locales with this fix.

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Commit messages:
 - 8333427: langtools/tools/javac/newlines/NewLineTest.java is failing on Japanese Windows

Changes: https://git.openjdk.org/jdk/pull/19519/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19519&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8333427
  Stats: 4 lines in 1 file changed: 1 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/19519.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19519/head:pull/19519

PR: https://git.openjdk.org/jdk/pull/19519