Allow calling miqps_highs() with HiPO solver selected (for LP problems).

Author: rdzman

lib/miqps_highs.m

@@ -272,9 +272,16 @@
     names = struct( ...
         'choose', 'default', ...
         'simplex', 'dual simplex', ...
-        'ipm', 'interior point', ...
+        'ipm', 'interior point (auto)', ...
+        'ipx', 'interior point (IPX)', ...
+        'hipo', 'interior point (HiPO)', ...
         'pdlp', 'primal-dual hybrid gradient' );
-    fprintf('HiGHS Version %s -- %s %s solver\n', vn, names.(solver), lpqp);
+    if ismember(solver, fieldnames(names))
+        solver_name =  names.(solver);
+    else
+        solver_name = 'unknown';
+    end
+    fprintf('HiGHS Version %s -- %s %s solver\n', vn, solver_name, lpqp);
 end
 [soln, info, opts, basis] = callhighs(c, A, l, u, xmin, xmax, H, integrality, highs_opt);
 if verbose