0.58.1

Fix missing "runtime_info" package documentation

The documentation for the "runtime_info" package wasn't being generated. We've fixed that oversight.

Use the correct LLVM intrinsics for powi on *nix.

We were using outdated LLVM intrinsics llvm.powi.f32j and llvm.powi.f64; updated to use llvm.powi.f32.i32 and llvm.powi.f64.i32.