xORBDB6/xUNBDB6: use safe termination criterion

With a modest amount of random testing on a work station, it is possible
to detect the loss of orthogonality caused by the old early termination
criterion.

Author: christoph-conrads

SRC/cunbdb6.f

@@ -173,7 +173,7 @@ SUBROUTINE CUNBDB6( M1, M2, N, X1, INCX1, X2, INCX2, Q1, LDQ1, Q2,
 *
 *     .. Parameters ..
       REAL               ALPHA, REALONE, REALZERO
-      PARAMETER          ( ALPHA = 0.1E0, REALONE = 1.0E0,
+      PARAMETER          ( ALPHA = 0.83E0, REALONE = 1.0E0,
      $                     REALZERO = 0.0E0 )
       COMPLEX            NEGONE, ONE, ZERO
       PARAMETER          ( NEGONE = (-1.0E0,0.0E0), ONE = (1.0E0,0.0E0),

SRC/dorbdb6.f

@@ -173,7 +173,7 @@ SUBROUTINE DORBDB6( M1, M2, N, X1, INCX1, X2, INCX2, Q1, LDQ1, Q2,
 *
 *     .. Parameters ..
       DOUBLE PRECISION   ALPHA, REALONE, REALZERO
-      PARAMETER          ( ALPHA = 0.1D0, REALONE = 1.0D0,
+      PARAMETER          ( ALPHA = 0.83D0, REALONE = 1.0D0,
      $                     REALZERO = 0.0D0 )
       DOUBLE PRECISION   NEGONE, ONE, ZERO
       PARAMETER          ( NEGONE = -1.0D0, ONE = 1.0D0, ZERO = 0.0D0 )

SRC/sorbdb6.f

@@ -173,7 +173,7 @@ SUBROUTINE SORBDB6( M1, M2, N, X1, INCX1, X2, INCX2, Q1, LDQ1, Q2,
 *
 *     .. Parameters ..
       REAL               ALPHA, REALONE, REALZERO
-      PARAMETER          ( ALPHA = 0.1E0, REALONE = 1.0E0,
+      PARAMETER          ( ALPHA = 0.83E0, REALONE = 1.0E0,
      $                     REALZERO = 0.0E0 )
       REAL               NEGONE, ONE, ZERO
       PARAMETER          ( NEGONE = -1.0E0, ONE = 1.0E0, ZERO = 0.0E0 )

SRC/zunbdb6.f

@@ -173,7 +173,7 @@ SUBROUTINE ZUNBDB6( M1, M2, N, X1, INCX1, X2, INCX2, Q1, LDQ1, Q2,
 *
 *     .. Parameters ..
       DOUBLE PRECISION   ALPHA, REALONE, REALZERO
-      PARAMETER          ( ALPHA = 0.1D0, REALONE = 1.0D0,
+      PARAMETER          ( ALPHA = 0.83D0, REALONE = 1.0D0,
      $                     REALZERO = 0.0D0 )
       COMPLEX*16         NEGONE, ONE, ZERO
       PARAMETER          ( NEGONE = (-1.0D0,0.0D0), ONE = (1.0D0,0.0D0),