Producing a new build of the JDK for each minor version of RHEL introduces a lot of overhead in development time (porting between branches), build time and testing.

Instead of creating an entirely new build for each minor version, we intend to make the RHEL RPM depend on the portable build (java-1.8.0-openjdk-portable*), with the build stage being replaced by the extraction of the portable build tarball. The later stages of the RPM build process will then proceed as before, as if the build had been created within that build.