In petsc.hpp, move the global declaration of PETSc types like Vec, Mat, KSP into the namespace mfem::petsc. These types are just aliases of the global PETSc types defined in PETSc's header petsc.h.
In petsc.hpp, move the global declaration of PETSc types like
Vec, Mat, KSP into the namespace mfem::petsc. These types are
just aliases of the global PETSc types defined in PETSc's
header petsc.h.

mfem/mfem,mfem/mfem,mfem/mfem,mfem/mfem,mfem/mfem