[binutils-gdb] Append -g -Os rather than overwriting

[sergiodj+buildbot@redhat.com]

*** TEST RESULTS FOR COMMIT bd51a4d5570d3e1dd9aae1e45db6ae087f2b645d ***

Author: H.J. Lu <hjl.tools@gmail.com>
Branch: master
Commit: bd51a4d5570d3e1dd9aae1e45db6ae087f2b645d

Append -g -Os rather than overwriting
	Sync with GCC
	2014-11-17  Bob Dunlop  <bob.dunlop@xyzzy.org.uk>

	* mt-ospace (CFLAGS_FOR_TARGET): Append -g -Os rather than
	overwriting.
	(CXXFLAGS_FOR_TARGET): Similarly.