openjdk/jdk ? reverse-engineered prompt

I want to build the latest version of the Java Development Kit (JDK) from this source code. It looks like this is the main OpenJDK project, which provides the tools needed to compile and run Java programs. The build process seems pretty complex with all the Makefiles and configuration scripts, so I'm going to need you to figure out the required dependencies and steps.

The README points to a building.md file in the doc folder; please follow those instructions carefully. You might need to look up current docs online if anything is unclear. The end goal is to have a complete, working JDK compiled on my machine, including the Java compiler (javac) and the runtime environment.