RFR: 8275536: [TEST] java.io.File and java.nio.File should return the same timestamp for lastModified

[Clive Verghese]

The test validated that the precision returned by `java.io.File.lastModified` and `java.nio.file.Files.getLastModifiedTime` are the same.

-------------

Commit messages:
 - 8275536: [TEST] java.io.File and java.nio.File should return the same timestamp for lastModified

Changes: https://git.openjdk.java.net/jdk/pull/6054/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6054&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/jdk/pull/6054.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6054/head:pull/6054

PR: https://git.openjdk.java.net/jdk/pull/6054