(store_symval_forwarding): Add parameter BUF. If BUF is

(store_symval_forwarding): Add parameter BUF.  If BUF is
non-null, set a per-buffer value in BUF instead of the current
buffer.
(swap_in_global_binding, swap_in_symval_forwarding, Fset_default):
Call store_symval_forwarding with BUF null.
(set_internal): Call store_symval_forwarding with the BUF
parameter passed to set_internal.  Formerly, the value was always
set in the current buffer; the buffer recorded in specbind for
this case wasn't used.
(arith_driver): Reindent.