Reimplement the JDK in Scala Native

Scala Native is a new target for Scala. It uses llvm to compile Scala to native assembly code, instead of compiling it to JVM bytecode. However, as compiling Java to llvm is not supported, there is a need to reimplement parts of the JDK. As it is currently work in progress, I could help contributors to achieve this goal. One of the most important milestones is implementing JDK API to support concurrency in Scala Native. This would be the core part of coding during the GSOC program. If finished before the end of the program, together with my mentor and the rest of contributors, I would look for other parts of the JDK API to implement.