* builtins.c (c_strlen): Add new parameter eltsize.  Use it
	for determining how to count the elements.
	* builtins.h (c_strlen): Adjust prototype.
	* expr.c (string_constant): Add new parameter mem_size.
	Set *mem_size appropriately.
	* expr.h (string_constant): Adjust protoype.
	* gimple-fold.c (get_range_strlen): Add new parameter eltsize.
	* gimple-fold.h (get_range_strlen): Adjust prototype.
	* gimple-ssa-sprintf.c (get_string_length): Add new parameter eltsize.
	(format_string): Call get_string_length with eltsize.

From-SVN: r263607