Fix 64-bit index bug found by compiler warning

extern/patch/metis/patch_build.diff

@@ -124,3 +124,43 @@ index 3fb0e6e..6e88b53 100644
        return;
 
      if (graph->nbnd > 0)
+diff --git a/libmetis/parmetis.c b/libmetis/parmetis.c
+index 631d811..418b606 100644
+--- a/libmetis/parmetis.c
++++ b/libmetis/parmetis.c
+@@ -308,7 +308,7 @@ void FM_2WayNodeRefine1SidedP(ctrl_t *ctrl, graph_t *graph,
+     * Get into the FM loop
+     *******************************************************/
+     mptr[0] = nmind = nbad = 0;
+-    mindiff = abs(pwgts[0]-pwgts[1]);
++    mindiff = iabs(pwgts[0]-pwgts[1]);
+     for (nswaps=0; nswaps<nvtxs; nswaps++) {
+       if ((higain = rpqGetTop(queue)) == -1) 
+         break;
+@@ -333,7 +333,7 @@ void FM_2WayNodeRefine1SidedP(ctrl_t *ctrl, graph_t *graph,
+
+       pwgts[2] -= (vwgt[higain]-rinfo[higain].edegrees[from]);
+
+-      newdiff = abs(pwgts[to]+vwgt[higain] - (pwgts[from]-rinfo[higain].edegrees[from]));
++      newdiff = iabs(pwgts[to]+vwgt[higain] - (pwgts[from]-rinfo[higain].edegrees[from]));
+       if (pwgts[2] < mincut || (pwgts[2] == mincut && newdiff < mindiff)) {
+         mincut      = pwgts[2];
+         mincutorder = nswaps;
+@@ -537,7 +537,7 @@ void FM_2WayNodeRefine2SidedP(ctrl_t *ctrl, graph_t *graph,
+     * Get into the FM loop
+     *******************************************************/
+     mptr[0] = nmind = 0;
+-    mindiff = abs(pwgts[0]-pwgts[1]);
++    mindiff = iabs(pwgts[0]-pwgts[1]);
+     to = (pwgts[0] < pwgts[1] ? 0 : 1);
+     for (nswaps=0; nswaps<nvtxs; nswaps++) {
+       u[0] = rpqSeeTopVal(queues[0]);  
+@@ -580,7 +580,7 @@ void FM_2WayNodeRefine2SidedP(ctrl_t *ctrl, graph_t *graph,
+
+       pwgts[2] -= (vwgt[higain]-rinfo[higain].edegrees[other]);
+
+-      newdiff = abs(pwgts[to]+vwgt[higain] - (pwgts[other]-rinfo[higain].edegrees[other]));
++      newdiff = iabs(pwgts[to]+vwgt[higain] - (pwgts[other]-rinfo[higain].edegrees[other]));
+       if (pwgts[2] < mincut || (pwgts[2] == mincut && newdiff < mindiff)) {
+         mincut      = pwgts[2];
+         mincutorder = nswaps;