[javadoc] the test framework is not sanitizing the diagnostic output of the test.

The test framework used by javadoc does not sanitize the output, resulting in malformed
unicode escapes causing jtreg's junit converter to fail.

parent.document.title="Overview (Testing \\"Window \\'Title\\'\\" with a \\\\ backslash and a / forward slash and a \\u00E8 unicode char also a tab and also a \\t special character another \\u0002 unicode))"; in 8016675/overview-summary.html$
$
Running subtest #2... Passed$
not found:$
parent.document.title="Overview (Testing "Window 'Title'" with a \\ backslash and a / forward slash and a \u00e8 unicode char also a tab and also a ^I special character another \u0002 unicode))"; in 8016675/overview-summary.html$

Note in the second case we have a single \ instead of \\.

Attached is the jtr, in order to test this to make sure that there are no illegal
characters, run jtreg -xml:verify <all-the-other-usual-options>