[CIR][ThroughMLIR] Add TanOp Lowering

[goxul]

Adds implementation for TanOp's lowering via ThroughMLIR.

[goxul]

Hey @bcardosolopes , I am a new contributor to this project, and I've created a small PR to get the hang of things.

Similar to the PRs here, here, I implemented a lowering for Tan (which I saw was missing). I'll add the lit test for it soon. Couple of questions:

1. Is there some form of formatter that I need to run before I check-in the code?
2. Is there any other test that I need to add, other than the lit test?

Thanks!

[bcardosolopes]

Hi, thanks for the PR

Is there some form of formatter that I need to run before I check-in the code?

Yes, you need to use clang-format, code style in https://llvm.org/docs/CodingStandards.html

Is there any other test that I need to add, other than the lit test?

A lit test is enough for this PR, please add one!

[bcardosolopes]

After you add the test please move this out of draft!

[github-actions]

✅ With the latest revision this PR passed the C/C++ code formatter.

[bcardosolopes]

LGTM, thanks!