[jdk11u-dev] RFR: 8275536: Add test to check that File::lastModified returns same time stamp as Files.getLastModifiedTime

[Goetz Lindenmaier]

I backport this for parity with 11.0.15-oracle.

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Commit messages:
 - Backport 97d3280eb4735f5b84cd4a9a1286e35c1c48113a

Changes: https://git.openjdk.java.net/jdk11u-dev/pull/737/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk11u-dev&pr=737&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8275536
  Stats: 60 lines in 1 file changed: 60 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk11u-dev/pull/737.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk11u-dev pull/737/head:pull/737

PR: https://git.openjdk.java.net/jdk11u-dev/pull/737