CLARSCL2 performs a reciprocal diagonal scaling on an vector:
   x <-- inv(D) * x
 where the REAL diagonal matrix D is stored as a vector.

 Eventually to be replaced by BLAS_cge_diag_scale in the new BLAS
 standard.

          M is INTEGER
     The number of rows of D and X. M >= 0.

          N is INTEGER
     The number of columns of D and X. N >= 0.

          D is REAL array, length M
     Diagonal matrix D, stored as a vector of length M.

          X is COMPLEX array, dimension (LDX,N)
     On entry, the vector X to be scaled by D.
     On exit, the scaled vector.

          LDX is INTEGER
     The leading dimension of the vector X. LDX >= 0.