FlushFormat int comp writing (BLAST-WarpX#6130)

This PR fixes an indexing bug related to writing integer components of
particles in WarpX.

This PR fixes a bug in PR BLAST-WarpX#5969, where an integer value is added to the
particle container at runtime and an error occurs on restarts.

Author: JustinRayAngus

Source/Diagnostics/FlushFormats/FlushFormatCheckpoint.cpp

@@ -235,10 +235,12 @@ FlushFormatCheckpoint::CheckpointParticles (
         // and the int comps
         int_names.resize(pc->NumIntComps());
         write_int_comps.resize(pc->NumIntComps());
+        //   note: inames and h_redistribute_int_comp are not the same size
         auto inames = pc->GetIntSoANames();
+        std::size_t const i0_redist = pc->h_redistribute_int_comp.size() - inames.size();
         for (std::size_t index = 0; index < inames.size(); ++index) {
             int_names[index] = inames[index];
-            write_int_comps[index] = pc->h_redistribute_int_comp[index];
+            write_int_comps[index] = pc->h_redistribute_int_comp[i0_redist + index];
         }
 
         pc->Checkpoint(dir, part_diag.getSpeciesName(),

Source/Diagnostics/FlushFormats/FlushFormatPlotfile.cpp

@@ -409,10 +409,12 @@ FlushFormatPlotfile::WriteParticles(const std::string& dir,
         // and the int comps
         int_names.resize(tmp.NumIntComps());
         int_flags.resize(tmp.NumIntComps());
+        //   note: inames and h_redistribute_int_comp are not the same size
         auto inames = tmp.GetIntSoANames();
+        std::size_t const i0_redist = tmp.h_redistribute_int_comp.size() - inames.size();
         for (std::size_t index = 0; index < inames.size(); ++index) {
             int_names[index] = inames[index];
-            int_flags[index] = tmp.h_redistribute_int_comp[index];
+            int_flags[index] = tmp.h_redistribute_int_comp[i0_redist + index];
         }
 
         const auto mass = pc->AmIA<PhysicalSpecies::photon>() ? PhysConst::m_e : pc->getMass();