Combine two existing mechanisms for copying symbol attributes, and fix a bug:

Combine two existing mechanisms for copying symbol attributes, and fix a bug:

* symbols.c (copy_symbol_attributes): New function.  Copies BFD symbol flags
and calls OBJ_COPY_SYMBOL_ATTRIBUTES.
(resolve_symbol_value, case O_symbol): Call it, if X_add_number is zero.  Don't
call obj_frob_forward_symbol.
* read.c (pseudo_set): Call copy_symbol_attributes, but only if X_add_number is
zero.
* config/obj-elf.h (obj_frob_forward_symbol): Deleted.