RFR: 7903191: Fix build with "MAKEFLAGS=-j32". [v5]

[Jan Kratochvil]

> A parallel build needlessly errors out:
> /bin/sh: line 5: jtreg/build/classes/com/sun/javatest/regtest/tool/jars.properties: No such file or directory
> make: *** [jtreg.gmk:98: jtreg/build/classes/com/sun/javatest/regtest/tool/jars.properties] Error 1

Jan Kratochvil has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains two additional commits since the last revision:

 - Merge branch 'master' into parallelbuild
 - Fix build with "MAKEFLAGS=-j32".
   
   /bin/sh: line 5: jtreg/build/classes/com/sun/javatest/regtest/tool/jars.properties: No such file or directory
   make: *** [jtreg.gmk:98: jtreg/build/classes/com/sun/javatest/regtest/tool/jars.properties] Error 1

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

Changes:
  - all: https://git.openjdk.org/jtreg/pull/72/files
  - new: https://git.openjdk.org/jtreg/pull/72/files/e9af4536..ff5318e7

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jtreg&pr=72&range=04
 - incr: https://webrevs.openjdk.org/?repo=jtreg&pr=72&range=03-04

  Stats: 2084 lines in 70 files changed: 1869 ins; 55 del; 160 mod
  Patch: https://git.openjdk.org/jtreg/pull/72.diff
  Fetch: git fetch https://git.openjdk.org/jtreg.git pull/72/head:pull/72

PR: https://git.openjdk.org/jtreg/pull/72