RFR: 8261734: Some jtreg tests are failing with invalid setRectClip

[Alexey Ushakov]

Clamping clip rect to the destination area

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Commit messages:
 - 8261734: Some jtreg tests are failing with invalid setRectClip

Changes: https://git.openjdk.java.net/lanai/pull/193/files
 Webrev: https://webrevs.openjdk.java.net/?repo=lanai&pr=193&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8261734
  Stats: 20 lines in 1 file changed: 19 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/lanai/pull/193.diff
  Fetch: git fetch https://git.openjdk.java.net/lanai pull/193/head:pull/193

PR: https://git.openjdk.java.net/lanai/pull/193