[jdk8u-dev] RFR: 8256152: tests fail because of ambiguous method resolution

[Zdenek Zambersky]

Backport to fix test build failures.

Actually, it seems, that whether test build failures happen depends on jtreg used, as test class indirectly inherits from `org.testng.Assert`. (probably methods were added there, which introduced ambiguity)

After dealing with different test path on 8,  patch applies cleanly.

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Commit messages:
 - Backport 646c20022c73258bebf7c55b3e1992b62f5de042

Changes: https://git.openjdk.org/jdk8u-dev/pull/468/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=468&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8256152
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/468.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev.git pull/468/head:pull/468

PR: https://git.openjdk.org/jdk8u-dev/pull/468