Set up auxiliary domain for unrotated grid

  When ROTATE_INDEX is true, the model keeps both its rotated internal grid and
an unrotated grid for setting initialization and forcing.  When the model is run
in symmetric memory mode, there is an auxiliary non-symmetric domain that is
needed for reading in fields at velocity points.  The auxiliary domain in the
unrotated grid (G_in) was not being set previously, causing the model to fail to
run some cases when ROTATE_INDEX was true.  That auxiliary domain in the
unrotated grid is now being set up properly.  All answers and output are bitwise
identical for any cases that worked previously.

src/core/MOM.F90

@@ -2904,6 +2904,11 @@ subroutine initialize_MOM(Time, Time_init, param_file, dirs, CS, &
   if (CS%rotate_index) then
     G_in%ke = GV%ke
 
+    ! Allocate the auxiliary non-symmetric domain for debugging or I/O purposes.
+    if (CS%debug .or. G_in%symmetric) then
+      call clone_MOM_domain(G_in%Domain, G_in%Domain_aux, symmetric=.false.)
+    else ; G_in%Domain_aux => G_in%Domain ; endif
+
     allocate(u_in(G_in%IsdB:G_in%IedB, G_in%jsd:G_in%jed, nz), source=0.0)
     allocate(v_in(G_in%isd:G_in%ied, G_in%JsdB:G_in%JedB, nz), source=0.0)
     allocate(h_in(G_in%isd:G_in%ied, G_in%jsd:G_in%jed, nz), source=GV%Angstrom_H)