Hi.

As we as openSUSE started using -flto, I see it very handy to have
an option value that will automatically detect number of cores
that can be used for parallel LTRANS phase.

Thoughts?

gcc/ChangeLog:

2019-07-23  Martin Liska  <mliska@suse.cz>

	* doc/invoke.texi: Document the new option value.
	* lto-wrapper.c (cpuset_popcount): New function
	is a copy of libgomp/config/linux/proc.c.
	(init_num_threads): Likewise.
	(run_gcc): Support -flto=auto.
---
 gcc/doc/invoke.texi |   3 ++
 gcc/lto-wrapper.c   | 124 +++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 126 insertions(+), 1 deletion(-)