RFR: 8274856: Failing jpackage tests with fastdebug/release build

[Alexey Semenyuk]

The fix is to isolate C++ calls in the separate forked child process on Linux. 
This change requires the passing of JLI command line arguments and values of environment variables between two processes.

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Commit messages:
 - Whitespace clean up
 - 8274856: Failing jpackage tests with fastdebug/release build

Changes: https://git.openjdk.java.net/jdk/pull/6283/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6283&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8274856
  Stats: 278 lines in 8 files changed: 232 ins; 20 del; 26 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6283.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6283/head:pull/6283

PR: https://git.openjdk.java.net/jdk/pull/6283