* bitmap.h: Add explanation of sparse set as linked-list bitmap.
	* sbitmap.h: Add explanation about non-sparse sets as simple bitmap.
	(TEST_BIT): Make a static inline function for stronger type checking.
	(SET_BIT): Don't handle sbitmaps with popcount.
	(RESET_BIT): Likewise.
	(SET_BIT_WITH_POPCOUNT): New, like SET_BIT but with popcount.
	(RESET_BIT_WITH_POPCOUNT): New, like RESET_BIT but with popcount.
	* ebitmap.c (ebitmap_clear_bit): Use SET_BIT_WITH_POPCOUNT and
	RESET_BIT_WITH_POPCOUNT on wordmask bitmaps.
	(ebitmap_set_bit, ebitmap_and_into, ebitmap_and, ebitmap_ior_into,
	ebitmap_and_compl_into, ebitmap_and_compl): Likewise.
	* sparseset.h: Add explanation of sparse set representation.

From-SVN: r189888