Always add input_statement to statement_list

Always add input_statement to statement_list

I think this is safer than leaving an input_statement added during
open_input_bfds off the list.  There are a number of places that
fiddle with various lists and might be confused by an off-list
statement, eg. orphan handling.

	* ldlang.c (new_afile): Remove add_to_list parameter.
	(lang_add_input_file): Update new_afile calls.
	(lookup_name): Splice input_statement added by new_afile into
	statement_list after current input_file_chain entry.
	(lang_process): Update comment.