Adjust `String.decodeASCII` to deal with the possibility that `StringCoding.countPositives` can return a value less than the exact number of leading positive bytes. This is the likely cause of a number of intermittent but somewhat common errors on aarch64 tests in our CI.
------------- Commit messages: - Exhaustively consume ASCII bytes in String.decodeASCII Changes: https://git.openjdk.java.net/jdk/pull/7855/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7855&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8283325 Stats: 57 lines in 2 files changed: 57 ins; 0 del; 0 mod Patch: https://git.openjdk.java.net/jdk/pull/7855.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/7855/head:pull/7855 PR: https://git.openjdk.java.net/jdk/pull/7855
