TigerPiger/OpenJdk-with-personal-understanding

在OpenJDK中添加注释，包括个人理解

Welcome to the JDK!

For build instructions please see the online documentation, or either of these files:

• doc/building.html (html version)
• doc/building.md (markdown version)

See https://openjdk.java.net/ for more information about the OpenJDK Community and the JDK.