[Truffle] Include a comparison between release and head in the benchmark report.
Stop using the deprecated verson of sun.misc.Unsafe#getLong(Object, int) and use the recommended getLong(Object, long).  The deprecated version is not present on Dalvik (Android) and throws Exception(Java::JavaLang::NoSuchMethodError): sun.misc.Unsafe.getLong
[Truffle] Remove GeneralConversions class, and more utilities into their classes.
[Truffle] Store fully boxed Fixnums as long, rather than int.
[Truffle] Support long Fixnums alongside int Fixnums.
Merge branch master into truffle-head.