Simple AXPY examples

There are three different versions of this computation.

1. Example with embeded tuning specification and a single Unroll annotation

orcc -v axpy5.c

2. Example with a separate tuning spec file

orcc -v -s axpy5.spec axpy5-nospec.c

3. Example with embedded tuning specification containing a Composite annotation

orcc -v axpy5a.c
