Need to better way to change endianess

[pluto699]

sbe-code-gen/app/generation/cpp/templates/generate.tmpl

Lines 40 to 48 in d4b2409

	{% if size == 8 %}
	{{ val }} = __builtin_bswap64({{ val }});
	{% elif size == 4 %}
	{{ val }} = __builtin_bswap32({{ val }});
	{% elif size == 2 %}
	{{ val }} = __builtin_bswap16({{ val }});
	{% else %}
	// fu
	{% endif %}

__builtin_... return non-floating point for floating point type

[pluto699]

https://godbolt.org/z/v5f4hPWTs