[exec.run.loop] update run_loop count representation to use code format

[ericniebler]

[run.loop.members]/p2 ends with two periods.

i notice also that the whole [exec.run.loop] section is inconsistent about putting numbers in code font. this pr addresses the issue by uniformly applying \tcode to numbers.

[eisenwave]

The two-period issue seems to be fixed already. I'm not sure whether it's correct to use code font or not here.

Code font implies that an operation is performed with an int literal, and that isn't always what we want to express.

"is 0" in particular is almost guaranteed to be wrong, unless it's certain that whatever "is 0" is also of type int. It could be argued that 0ll "equals 0" or "is 0", but not that it "is 0".

[ericniebler]

I don't care which way we go, but I do want things to be consistent.

As a data point, we always put true and false in code font.

[jensmaurer]

Since there are no exposition-only data members involved here, but we're talking about the abstract property "count", it seems more appropriate to use math-style numbers here (i.e. no decoration) than code-style numbers. After all, those numbers stay in the abstract math domain.

(For example, we don't say anywhere that the "count" can ever overflow, and what it means to do so.)