RFR: 8023814: Test java/awt/im/memoryleak/InputContextMemoryLeakTest.java fails

[Alexander Zvegintsev]

Removing the test from problem list, since I am unable to reproduce the issue even with old Ubuntu distros with jdk8.
Bug filed against Solaris initially, but I did not test on it, since it is no longer supported.

Multiple mach5 testing is green.

`dispose` added for convenience if test is executed without jtreg.

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

Commit messages:
 - initial

Changes: https://git.openjdk.java.net/jdk/pull/8295/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8295&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8023814
  Stats: 9 lines in 2 files changed: 5 ins; 2 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8295.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8295/head:pull/8295

PR: https://git.openjdk.java.net/jdk/pull/8295