bitmap.c (bitmap_obstack_alloc_stat): Adjust cast to eliminate C++ warning about implicit conversion from void * to...

	* bitmap.c (bitmap_obstack_alloc_stat): Adjust cast to eliminate
	C++ warning about implicit conversion from void * to struct
	bitmap_head_def *.
	(bitmap_obstack_free): Likewise for bitmap_element *.

From-SVN: r143480