Add toString() implementation that follows "shortest string" conventions.
Follow-up testing to be done under JDK-8375224: Add tests for Bfloat16.toString(). ------------- Commit messages: - 8375223: Add proper toString output to bfloat16 implementation Changes: https://git.openjdk.org/valhalla/pull/1900/files Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1900&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8375223 Stats: 159 lines in 1 file changed: 75 ins; 23 del; 61 mod Patch: https://git.openjdk.org/valhalla/pull/1900.diff Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1900/head:pull/1900 PR: https://git.openjdk.org/valhalla/pull/1900
