Add in the makefile rules and JPRT properties that enable the hotspot workspace to be built by JPRT.

This involves defining the jprt_build makefile rule in make/Makefile, and adding in the jprt.properties file into the make directory that defines JPRT properties specific to this workspace.

The jprt_build rule should build the hotspot libraries and create a zip file defined in the make variable JPRT_ARCHIVE_BUNDLE.

The workspace gets to decide what gets put in this bundle, but the expectation is that it is a JDK install tree that can be unzipped to create at a minumum the bin, include, lib, and jre directories.