* configure.target (cpu_include_dir): Set to `config/cpu/m68k' for

	m68k and m680[246]0.
	* config/cpu/m68k/bits/atomicity.h: New file.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@44925 138bc75d-0d04-0410-961f-82ee72b054a4