[vector] Keeping the samples updated

[Brian Goetz]

As we go through our several rounds of API realignment, we'll surely 
cause some disruption to users who have been trying the code out as we 
go.  For example, the examples on this page:

https://software.intel.com/en-us/articles/vector-api-developer-program-for-java

no longer compile.  Perhaps we could include, in our tests directory, 
some "example" code which is kept compiling as we update the API, so 
users always have known-good code to cut and paste from to get them 
started?