combine.c (simplify_comparison): Add canonical FALLTHROUGH comments.

	* combine.c (simplify_comparison): Add canonical FALLTHROUGH comments.
	* config/i386/i386.c (ix86_dep_by_shift_count_body): Add FALLTHROUGH
	comments.  Remove break after return.
	(ix86_fp_compare_code_to_integer, has_dispatch,
	ix86_simd_clone_usable): Remove break after return.

From-SVN: r240523