hg: jdk/sandbox: 8239243: Create index structures only if required

[chris.hegarty at oracle.com]

Changeset: 80e403e1ff94
Author:    prappo
Date:      2020-02-19 10:34 +0000
URL:       https://hg.openjdk.java.net/jdk/sandbox/rev/80e403e1ff94

8239243: Create index structures only if required
Reviewed-by: hannesw, jjg

! src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/AbstractIndexWriter.java
! src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/AllClassesIndexWriter.java
! src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/HtmlDoclet.java
! src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/SingleIndexWriter.java
! src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/SplitIndexWriter.java
! src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/toolkit/util/IndexBuilder.java