Add C++ subset unit tests for vector_base::insert().
Add C++ subset unit tests for vector_base::insert().

malenie/thrust,UIKit0/thrust,bfurtaw/thrust,levendlee/thrust,allendaicool/thrust,h1arshad/thrust,julianromera/thrust,google-code-export/thrust,UIKit0/thrust,levendlee/thrust,rdmenezes/thrust,google-code-export/thrust,UIKit0/thrust,malenie/thrust,malenie/thrust,allendaicool/thrust,hemmingway/thrust,google-code-export/thrust,bfurtaw/thrust,h1arshad/thrust,Vishwa07/thrust,google-code-export/thrust,rdmenezes/thrust,hemmingway/thrust,Vishwa07/thrust,julianromera/thrust,bfurtaw/thrust,hemmingway/thrust,h1arshad/thrust,Vishwa07/thrust,lishi0927/thrust,UIKit0/thrust,Vishwa07/thrust,bfurtaw/thrust,allendaicool/thrust,lishi0927/thrust,hemmingway/thrust,lishi0927/thrust,julianromera/thrust,h1arshad/thrust,julianromera/thrust,malenie/thrust,levendlee/thrust,lishi0927/thrust,allendaicool/thrust,levendlee/thrust,rdmenezes/thrust,rdmenezes/thrust