Add the (2,4,9) template specialization for PartitionedMatrixView
and SchurEliminator.

Also update the comment inside generate_partitioned_matrix_view_specializations.py

Change-Id: I99a7ab4256091b1da48553da3076e5996a5757ed
diff --git a/internal/ceres/schur_eliminator.cc b/internal/ceres/schur_eliminator.cc
index 25103dc..2701683 100644
--- a/internal/ceres/schur_eliminator.cc
+++ b/internal/ceres/schur_eliminator.cc
@@ -102,6 +102,11 @@
   }
   if ((options.row_block_size == 2) &&
       (options.e_block_size == 4) &&
+      (options.f_block_size == 9)) {
+    return new SchurEliminator<2, 4, 9>(options);
+  }
+  if ((options.row_block_size == 2) &&
+      (options.e_block_size == 4) &&
       (options.f_block_size == Eigen::Dynamic)) {
     return new SchurEliminator<2, 4, Eigen::Dynamic>(options);
   }