[llvm] [mlir] [mlir][EmitC] Add MathToEmitC pass for math function lowering to EmitC (PR #113799)

[Marius Brehler via llvm-commits]

marbre wrote:

Before we can merge, can you please update the PR description to reflect the current state? The PR description will become the body of the commit message when squashing. Furthermore, according to the Developer Policy, can you please disable that your email address is kept private?

https://llvm.org/docs/DeveloperPolicy.html#making-and-submitting-a-patch
> The LLVM project uses email to communicate to contributors outside of the GitHub platform about their past contributions. Primarily, our buildbot infrastructure uses emails to contact contributors about build and test failures. Therefore, the LLVM community requires contributors to have a public email address associated with their GitHub commits, so please ensure that “Keep my email addresses private” is disabled in your [account settings](https://github.com/settings/emails).

https://github.com/llvm/llvm-project/pull/113799