Fix nonexistent overload of Printf functionality

[Seelengrab]

BFloat16s.jl/src/printf.jl

Lines 10 to 17 in ef6051e

	else
	fix_dec(out, d::BFloat16, flags::String, width::Int, precision::Int, c::Char, digits) = fix_dec(out, Float32(d), flags, width, precision, c, digits)
	ini_dec(out, d::BFloat16, ndigits::Int, flags::String, width::Int, precision::Int, c::Char, digits) = ini_dec(out, Float32(d), ndigits, flags, width, precision, c, digits)
	ini_hex(out, d::BFloat16, ndigits::Int, flags::String, width::Int, precision::Int, c::Char, digits) = ini_hex(out, Float32(d), ndigits, flags, width, precision, c, digits)
	ini_HEX(out, d::BFloat16, ndigits::Int, flags::String, width::Int, precision::Int, c::Char, digits) = ini_HEX(out, Float32(d), ndigits, flags, width, precision, c, digits)
	ini_hex(out, d::BFloat16, flags::String, width::Int, precision::Int, c::Char, digits) = ini_hex(out, Float32(d), flags, width, precision, c, digits)
	ini_HEX(out, d::BFloat16, flags::String, width::Int, precision::Int, c::Char, digits) = ini_HEX(out, Float32(d), flags, width, precision, c, digits)
	end

These lines should probably be replaced with functions from Base.Ryu. I think this has been broken since at least 1.6.

[JeffreySarnoff]

happy to do so -- no idea what to do though