PR middle-end/78703 - -fprintf-return-value floating point handling incorrect in locales with a mulltibyte decimal point
	* gimple-ssa-sprintf.c (warn_level): New global.
	(format_integer): Use it here and throughout the rest of the file.
	Use the same switch to compute sign as base.
	(maybe_warn): New function.
	(format_directive): Factor out warnings into maybe_warn.
	Add debugging output.  Use warn_level.
	(add_bytes): Use warn_level.
	(pass_sprintf_length::compute_format_length): Add debugging output.
	(try_substitute_return_value): Same.
	(pass_sprintf_length::handle_gimple_call): Set and use warn_level.

From-SVN: r244847