Add test generator using python mako templates.

* Adds templates for OPIVV, OPIVX and OPIVI instruction tests.
* Adds cmake targets for generating test source code.
* Convert vsub and vadd to autogenerated tests.
* Remove vand test.

Change-Id: I1a197894e83e7ae23841e5164eac6e13186f9c09
10 files changed