Allow passing a Callable to Log::debug() (and related)

[jkoop]

For example, I'm looping over some data in a very convoluted way (due to nature of the problem my code solves), but it crashes when given some sort of edge-case data, so I need to debug it.

Right now I'm using this:

// in my huge loop
Log::debug($lineNumber + 1 . ' of ' . count($lines));

However, count() will be run (and take CPU time) even in prod; it'd be nice if I could do this:

// in my huge loop
Log::debug(fn () => $lineNumber + 1 . ' of ' . count($lines));

Because then, count() will only be run when logging.

I quickly glanced at the code and it seems to be pretty easy to implement. Should I give it a stab?

[jkoop]

I stabbed it. Here's the PR.