RFR: 8288021: Add hard test cases to jdk.internal.math.DoubleToDecimalChecker

[Raffaello Giulietti]

These 19'545 doubles were generated on purpose by Paul Zimmermann of INRIA as hard test cases.

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Commit messages:
 - 8288021: Add hard test cases to jdk.internal.math.DoubleToDecimalChecker

Changes: https://git.openjdk.java.net/jdk/pull/9084/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=9084&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8288021
  Stats: 19594 lines in 1 file changed: 19594 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/9084.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/9084/head:pull/9084

PR: https://git.openjdk.java.net/jdk/pull/9084