8290313: Produce warning when user specified java.io.tmpdir directory doesn't exist
------------- Commit messages: - new approach - change based on the review - updating according to the comments - Merge branch 'master' of https://github.com/openjdk/jdk into improve-directory-not-existing-error-message - update error message - error message for non-existing directory - improve error message when file directory does not exist Changes: https://git.openjdk.org/jdk/pull/9989/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9989&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8290313 Stats: 82 lines in 3 files changed: 79 ins; 0 del; 3 mod Patch: https://git.openjdk.org/jdk/pull/9989.diff Fetch: git fetch https://git.openjdk.org/jdk pull/9989/head:pull/9989 PR: https://git.openjdk.org/jdk/pull/9989
