Infinity fix and clang from PPA

[daschuer]

No description provided.

[Swiftb0y]

introducing util_*_infinity still opening a hellscape to undefined behavior...

[Swiftb0y]

Suggested change

	float util_float_infinity() {
	return std::numeric_limits<double>::infinity();
	}
	float util_float_infinity() {
	return std::numeric_limits<float>::infinity();
	}

[JoergAtGithub]

@daschuer Thank you very much for setting up the Clazy PPA! I cherry-picked this into mixxxdj#13781
But I will not do the same for the commit with the inifinity fix. This is because:
1.) This would be an unrelated scope expansion of my PR
2.) As written 3 weeks ago in mixxxdj#13780, there is no consensus about the fplcassify approach in general. The expected discussion would uneccessarily delay my PR.
3.) If we agree on a fix, this should go into the stable branch, as this is also affected

Therefore please create an independent PR against 2.4, where we can discuss this fix seperately.