This is a subtask of [JDK-8286091](https://bugs.openjdk.org/browse/JDK-8286091) which is aiming to improve XPath expression test coverage. The goal of this subtask is validating the XPath child axis specifier in various ways.
------------- Commit messages: - Added more XPath expression test cases and created negative tests for invalid expressions. - Created XPathChildTest.java Changes: https://git.openjdk.org/jdk/pull/9484/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9484&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8289511 Stats: 217 lines in 1 file changed: 217 ins; 0 del; 0 mod Patch: https://git.openjdk.org/jdk/pull/9484.diff Fetch: git fetch https://git.openjdk.org/jdk pull/9484/head:pull/9484 PR: https://git.openjdk.org/jdk/pull/9484
