Add PECInsulator to Curl-Curl BC (#5667)

This is a temporary fix, setting a boundary condition for the Curl-Curl
preconditioner for the implicit solver. This now sets the BC to
Dirichlet for the PEC regions. A correct solution would have to be
implemented in the curl-curl solver because of the split between the PEC
and insulator sections.

Source/FieldSolver/ImplicitSolvers/ImplicitSolver.cpp

@@ -68,7 +68,12 @@ Array<LinOpBCType,AMREX_SPACEDIM> ImplicitSolver::convertFieldBCToLinOpBC (const
             WARPX_ABORT_WITH_MESSAGE("LinOpBCType not set for this FieldBoundaryType");
         } else if (a_fbc[i] == FieldBoundaryType::Neumann) {
             // Also for FieldBoundaryType::PMC
-            lbc[i] = LinOpBCType::Neumann;
+            lbc[i] = LinOpBCType::symmetry;
+        } else if (a_fbc[i] == FieldBoundaryType::PECInsulator) {
+            ablastr::warn_manager::WMRecordWarning("Implicit solver",
+                "With PECInsulator, in the Curl-Curl preconditioner Neumann boundary will be used since the full boundary is not yet implemented.",
+                ablastr::warn_manager::WarnPriority::medium);
+            lbc[i] = LinOpBCType::symmetry;
         } else if (a_fbc[i] == FieldBoundaryType::None) {
             WARPX_ABORT_WITH_MESSAGE("LinOpBCType not set for this FieldBoundaryType");
         } else if (a_fbc[i] == FieldBoundaryType::Open) {