The getTagletOutput methods in BaseTaglet have obsolete JDK8-era comments, and throw inconsistent exceptions.

These should be cleaned up.

Here's a list of some bad references:
$ grep -r '<code>Tag</code>' open/src/jdk.javadoc
open/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/toolkit/taglets/Taglet.java: * Given the<code>Tag</code> representation of this custom
open/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/toolkit/taglets/Taglet.java: * @param tag the <code>Tag</code> representation of this custom tag.
open/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/toolkit/taglets/Taglet.java: * @return the Content representation of this <code>Tag</code>.
open/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/toolkit/taglets/Taglet.java: * @return the content representation of this <code>Tag</code>.
open/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/toolkit/taglets/BasePropertyTaglet.java: * Given the <code>Tag</code> representation of this custom
open/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/toolkit/taglets/BasePropertyTaglet.java: * @param tag the <code>Tag</code> representation of this custom tag.
open/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/toolkit/taglets/BasePropertyTaglet.java: * @return the TagletOutput representation of this <code>Tag</code>.
open/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/toolkit/taglets/ThrowsTaglet.java: * Given an array of <code>Tag</code>s representing this custom
open/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/toolkit/taglets/ThrowsTaglet.java: * @return the Content representation of this <code>Tag</code>.