Copy rho from guard cells in IGF solver (ECP-WarpX#5284)

* Copy rho from guard cells in IGF solver

* Reset checksum

Regression/Checksum/benchmarks_json/test_3d_open_bc_poisson_solver.json

@@ -1,20 +1,20 @@
 {
   "lev=0": {
-    "Bx": 100915933.44993827,
-    "By": 157610622.1855512,
-    "Bz": 9.717358898362187e-14,
-    "Ex": 4.7250652706211096e+16,
-    "Ey": 3.0253948990559976e+16,
-    "Ez": 3276573.9514776524,
-    "rho": 10994013582437.193
+    "Bx": 100915975.15792876,
+    "By": 157610677.31483692,
+    "Bz": 2.404060922276648e-13,
+    "Ex": 4.725066923361703e+16,
+    "Ey": 3.0253961494347724e+16,
+    "Ez": 3276584.4383433666,
+    "rho": 10994013582437.197
   },
   "electron": {
-    "particle_momentum_x": 5.701277606050295e-19,
-    "particle_momentum_y": 3.6504516641520437e-19,
+    "particle_momentum_x": 5.701279599504008e-19,
+    "particle_momentum_y": 3.650453172860547e-19,
     "particle_momentum_z": 1.145432768297242e-10,
-    "particle_position_x": 17.314086912497864,
-    "particle_position_y": 0.2583691267187796,
+    "particle_position_x": 17.31408691249785,
+    "particle_position_y": 0.2583691267187801,
     "particle_position_z": 10066.329600000008,
     "particle_weight": 19969036501.910976
   }
-}
+}

Source/ablastr/fields/IntegratedGreenFunctionSolver.cpp

@@ -75,7 +75,7 @@ computePhiIGF ( amrex::MultiFab const & rho,
     SpectralField tmp_G_fft = SpectralField( spectralspace_ba, dm_global_fft, 1, 0 );
 
     // Copy from rho to tmp_rho
-    tmp_rho.ParallelCopy( rho, 0, 0, 1, amrex::IntVect::TheZeroVector(), amrex::IntVect::TheZeroVector() );
+    tmp_rho.ParallelCopy( rho, 0, 0, 1, rho.nGrowVect(), amrex::IntVect::TheZeroVector() );
 
     // Compute the integrated Green function
     {