* hpcviewer: new package

Add binary package for hpcviewer and hpctraceviewer for the Rice
hpctoolkit on Linux x86_64, ppc64 and ppc64le.

* ibm-java: add property 'home' so that spec['java'].home will work.

* Flake

* More flake.

* Test that the version, machine type pair exists before using it in the
sha dictionaries so that 'spack info' doesn't crash on unsupported
configurations.