ZDRSCL multiplies an n-element complex vector x by the real scalar
 1/a.  This is done without overflow or underflow as long as
 the final result x/a does not overflow or underflow.

          N is INTEGER
          The number of components of the vector x.

          SA is DOUBLE PRECISION
          The scalar a which is used to divide each component of x.
          SA must be >= 0, or the subroutine will divide by zero.

          SX is COMPLEX*16 array, dimension
                         (1+(N-1)*abs(INCX))
          The n-element vector x.

          INCX is INTEGER
          The increment between successive values of the vector SX.
          > 0:  SX(1) = X(1) and SX(1+(i-1)*INCX) = x(i),     1< i<= n