JEP: JWarmup precompile java hot methods at application startup

[yumin qi]

Hi, Mark

  Proposed a draft of new JEP:
https://bugs.openjdk.java.net/browse/JDK-8203832

  We (Alibaba Group Inc) have an implementation of warmup performance
solution and want to contribute to OpenJDK, wish it can help java
developers to resolve the same problems we have encountered.

   Please take a look and wait for a discussion/evaluation on it.

Thanks
Yumin