Summary

Add a table of historic Unicode versions in the java.lang.Character class description.

Problem

Historic Unicode versions vs. Java releases have been documented in the JLS. However, it is burdensome to revise it each time Unicode is upgraded.

Solution

Moving the table into java.lang.Character class documentation is more maintainable, as the class description is always updated each time Unicode is upgraded.

Specification

Add the following paragraph and table into the Unicode Conformance section of the class description of java.lang.Character.

 * <p>
 * The Java platform has supported different versions of the Unicode
 * Standard over time. Upgrades to newer versions of the Unicode Standard
 * occurred in the following Java releases, each indicating the new version:
 * <table class="striped">
 * <caption style="display:none">Shows Java releases and supported Unicode versions</caption>
 * <thead>
 * <tr><th scope="col">Java release</th>
 *     <th scope="col">Unicode version</th></tr>
 * </thead>
 * <tbody>
 * <tr><td>Java SE 15</td>
 *     <td>Unicode 13.0</td></tr>
 * <tr><td>Java SE 13</td>
 *     <td>Unicode 12.1</td></tr>
 * <tr><td>Java SE 12</td>
 *     <td>Unicode 11.0</td></tr>
 * <tr><td>Java SE 11</td>
 *     <td>Unicode 10.0</td></tr>
 * <tr><td>Java SE 9</td>
 *     <td>Unicode 8.0</td></tr>
 * <tr><td>Java SE 8</td>
 *     <td>Unicode 6.2</td></tr>
 * <tr><td>Java SE 7</td>
 *     <td>Unicode 6.0</td></tr>
 * <tr><td>Java SE 5.0</td>
 *     <td>Unicode 4.0</td></tr>
 * <tr><td>Java SE 1.4</td>
 *     <td>Unicode 3.0</td></tr>
 * <tr><td>JDK 1.1</td>
 *     <td>Unicode 2.0</td></tr>
 * <tr><td>JDK 1.0.2</td>
 *     <td>Unicode 1.1.5</td></tr>
 * </tbody>
 * </table>
 * Variations from these base Unicode versions, such as recognized appendixes,
 * are documented elsewhere.