MFC r260334:

MFC r260334:

Split the last gcc-specific flags off into CFLAGS.gcc.  This also
removes the need to use -Qunused-arguments for clang throughout the
tree.

MFC r260369:

Apply band-aid for 32-bit compat libs failures after r260334: put back
-Qunused-arguments for clang for now, until I can figure out a way to
make it unneeded in all scenarios.  Sorry about the breakage.

git-svn-id: svn://svn.freebsd.org/base/stable/10@260497 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f