[binutils-gdb] Remove usage of find_inferior in iterate_over_lwps

[sergiodj+buildbot at sergiodj dot net]

*** TEST RESULTS FOR COMMIT 6d1e5673fec830f0f1c86632a5d9333e34582bb3 ***

Author: Simon Marchi <simon.marchi@ericsson.com>
Branch: master
Commit: 6d1e5673fec830f0f1c86632a5d9333e34582bb3

Remove usage of find_inferior in iterate_over_lwps

Replace find_inferior with find_thread.  Since it may be useful in the
future, I added another overload to find_thread which filters based on a
ptid (using ptid_t::matches), so now iterate_over_lwps doesn't have to
do the filtering itself.  iterate_over_lwps_filter is removed and
inlined into iterate_over_lwps.

gdb/gdbserver/ChangeLog:

	* gdbthread.h (find_thread): Add overload with ptid_t filter.
	* linux-low.c (struct iterate_over_lwps_args): Remove.
	(iterate_over_lwps_filter): Remove.
	(iterate_over_lwps): Use find_thread.