RFR 8167157: ant build fails with [javadoc] javadoc: error - Illegal package name: "implNote:a:Implementation Note:"

[Sundararajan Athijegannathan]

Please review http://cr.openjdk.java.net/~sundar/8167157/webrev.00/ for
https://bugs.openjdk.java.net/browse/JDK-8167157

PS. Note the whitespace before line continuation char "\". Apparently,
that is needed now with the latest jdk9-dev forest build! Don't know the
reason behind. But, this whitespace does fix the issue!

-Sundar