Example program for dorgtr

This example computes all the eigenvalues and eigenvectors of the matrix A, where
A = 2.07 3.87 4.20 -1.15 3.87 -0.21 1.87 0.63 4.20 1.87 1.15 2.06 -1.15 0.63 2.06 -1.81 .  
Here A is symmetric and must first be reduced to tridiagonal form by dsytrd. The program then calls dorgtr to form Q, and passes this matrix to dsteqr which computes the eigenvalues and eigenvectors of A.