This patch removes the argument of pointer to struct ld_plugin_input_file.
This is the first step to extract a plugin_object_p out of
plugin_maybe_claim for BFD.
* plugin.c: Include "libbfd.h".
(plugin_strdup): New.
(plugin_maybe_claim): Remove the argument of pointer to struct
ld_plugin_input_file. Open and handle input entry.
* plugin.h (plugin_maybe_claim): Updated.
* ldfile.c (ldfile_try_open_bfd): Call plugin_maybe_claim directly
without passing a pointer to struct ld_plugin_input_file.
* ldmain.c: Don't include "libbfd.h".
(add_archive_element): Call plugin_maybe_claim directly without
passing a pointer to struct ld_plugin_input_file.