* mpi/ec.c (_gcry_mpi_ec_point_resize): Export the routine
for internal use.
(add_points_edwards, _gcry_mpi_ec_mul_point): Use mpi_point_resize.
* src/gcrypt-int.h (_gcry_mpi_ec_point_resize): Declare.
* src/visibility.c (gcry_mpi_ec_dup, gcry_mpi_ec_add): Make sure for
the size of limb before calling the internal functions.
(gcry_mpi_ec_sub): Likewise.