RFR: JDK-8185669: Doc issues in assorted small jdk.* modules

[Jonathan Gibbons]

Please review another small set of doc fixes in some minor jdk.* modules.

JBS: https://bugs.openjdk.java.net/browse/JDK-8185669
Webrev: http://cr.openjdk.java.net/~jjg/8185669/webrev.00/

-- Jon