Simplify constant TimeSpan retrieval

[xtqqczze]

The JIT compiler can treat TimeSpan.FromMinutes(1) as a constant and optimize it at compile time. In contrast, TimeSpan.Parse involves runtime string parsing and cannot be constant-folded, which adds unnecessary overhead.

TimeSpan.Parse may also behave differently depending on culture settings.

[Clockwork-Muse]

TimeSpan.Parse may behave differently depending on culture settings.

This may be true, but the original version also only ran parameter validation/construction once.

[tannergooding]

It would be beneficial to share some diffs and/or benchmarks from this.

This looks like a pure improvement, but having the numbers just helps add the extra +1 to give people peace of mind.

[xtqqczze]

Diffs are an improvement, as expected.

[tannergooding]

Yep. Mostly looks like removing the static constructors (which should happen in T1 anyways) and that we do get the direct constant as expected.

[dotnet-policy-service]

Tagging subscribers to this area: @roji, @SamMonoRT
See info in area-owners.md if you want to be subscribed.

[tannergooding]

This LGTM, but since its in a less touched area I will defer to the area owners on whether it meets the bar for merge: @SamMonoRT, @roji