Request of implantmentation of lgamma function

I am trying to port an mlx implementation of the SCVI module of scvi-tools (a comprehensive de-batching approach using VAE models), which currently overcomes the problem of mlx.array not supporting scipy sparse matrices by converting the sparse matrices to dense matrices, but in practice I can only use python's internal lanczos approximation due to the lack of a native C++ backend lgamma function (something like torch.lgamma or jax.scipy.special.gamma) which leads to a severely limited code with high training loss, and I would like to request the implementation of a built in gamma as well as the lgamma function since I am completely lacking in C code capabilities.

The issue names no files or tests. Start by locating MLX's native C++ math-function entry points and existing special-function tests, then compare the requested gamma and lgamma behavior with the cited torch and JAX references. Done means both functions are available as built-in MLX operations with coverage for their expected behavior.