connected component label periodic boundary conditions

[burlen]

the cuda implementation needs to check the periodic bc conditions across cuda domain decomp. step 2 of the bard test can identify the issue if periodic bc is enabled. parameter table row 43 and 115 trigger the issue.

smic:~/work/teca/teca/bin-mpich$diff -u bard_test_step_2_cpu_out.txt ../mpich-bin-cpu/bard_test_step_2_gpu_out.txt 
--- bard_test_step_2_cpu_out.txt	2023-11-06 07:10:02.962644986 -0800
+++ ../mpich-bin-cpu/bard_test_step_2_gpu_out.txt	2023-11-06 07:05:15.192203178 -0800
@@ -41,7 +41,7 @@
 row_id=40  periodic_in_x=1  num_comps=4
 row_id=41  periodic_in_x=1  num_comps=9
 row_id=42  periodic_in_x=1  num_comps=7
-row_id=43  periodic_in_x=1  num_comps=7
+row_id=43  periodic_in_x=1  num_comps=8
 row_id=44  periodic_in_x=1  num_comps=4
 row_id=45  periodic_in_x=1  num_comps=7
 row_id=46  periodic_in_x=1  num_comps=3
@@ -113,7 +113,7 @@
 row_id=112  periodic_in_x=1  num_comps=3
 row_id=113  periodic_in_x=1  num_comps=9
 row_id=114  periodic_in_x=1  num_comps=4
-row_id=115  periodic_in_x=1  num_comps=9
+row_id=115  periodic_in_x=1  num_comps=10
 row_id=116  periodic_in_x=1  num_comps=11
 row_id=117  periodic_in_x=1  num_comps=3
 row_id=118  periodic_in_x=1  num_comps=5

bard_test_step_2_gpu_out.txt
bard_test_step_2_cpu_out.txt