Pass PC to caller marshaller to allow more detailed information

[Hades32]

Here the program counter var is _ ignored:

zerolog/event.go

Lines 743 to 753 in 4099072

	func (e *Event) caller(skip int) *Event {
	if e == nil {
	return e
	}
	_, file, line, ok := runtime.Caller(skip + e.skipFrame)
	if !ok {
	return e
	}
	e.buf = enc.AppendString(enc.AppendKey(e.buf, CallerFieldName), CallerMarshalFunc(file, line))
	return e
	}

If it was passed into the marshaller, we could also print the method name, which we're currently missing.

As this would be a backwards-incompatible change, I'm creating this issue first before creating a PR, but I think it would be worth it and very easy to fix (for the few people that actually overwrite that method manually)

Edit:
This is how you could get the func name:

.Str("func", runtime.FuncForPC(pc).Name())

[Hades32]

@rs should I create a PR or do you think breaking compatibility (a tiny bit) is a no-go?

[rs]

Sure go ahead

[Hades32]

Great, done @rs