RFR: 8334332: Run TestIOException.java with root user fails

Hi all, Test `test/langtools/jdk/javadoc/doclet/testIOException/TestIOException.java` run fails with root user privileged. I think it's necessary to skip this testcase when user is root. The change has been verified, only change the testcase, no risk. - Commit messages: - 83343

Re: RFR: 8334332: Run TestIOException.java with root user fails [v2]

> Hi all, > Test > `test/langtools/jdk/javadoc/doclet/testIOException/TestIOException.java` run > fails with root user privileged. I think it's necessary to skip this testcase > when user is root. > The change has been verified, only change the testcase, no risk. SendaoYan has updated the p