RFR: 8286551: JDK-8286460 causes tests to fail to compile in Tier2

[Calvin Cheung]

The tests fail compilation due to a missing import statement.

Simple fix to add the following import statement to the tests:

`import java.nio.file.Path`

Ran the tests successfully locally on linux-x64.

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Commit messages:
 - 8286551: JDK-8286460 causes tests to fail to compile in Tier2

Changes: https://git.openjdk.java.net/jdk/pull/8639/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8639&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8286551
  Stats: 16 lines in 14 files changed: 14 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8639.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8639/head:pull/8639

PR: https://git.openjdk.java.net/jdk/pull/8639