CIRGen support for `__builtin_tan`

[FantasqueX]

This is similar to #383
However, there is no TanOp in MLIR LLVM Dialect. Upstream PR llvm/llvm-project#125748 resolves this issue. After this PR being merged, CIRGen can be implemented easily.

[shrikardongre]

hey ! @FantasqueX I see the PR you mentioned as already merged.
If thats the case i would really love to make my first contribution here if you dont have any problem :)

[FantasqueX]

Hi @shrikardongre The problem is that this feature hasn't been merged into clangir code base. A rebase is needed.

[bcardosolopes]

Ok, created a label to track things blocked on rebases

[bcardosolopes]

@FantasqueX good job with the LLVM dialect fixes, if there are more issues like this one, feel free to start tagging around

[FantasqueX]

LLVM_TanOp is in clangir code base currently!

[el-ev]

I would like to take this.