[llvm] [LLVM] Factor disabled Libcalls into the initializer (PR #98421)

[Joseph Huber via llvm-commits]

jhuber6 wrote:

> Yup. Thank you for clarifying it. In that case, all RTlib calls should be disabled for NVPTX, as there's nothing on the GPU side to fulfill them at the moment, at least for the standard CUDA compilation.

You weren't the only one confused at the duplication here. I can make a patch to turn them off since I'll want it for NVPTX compilation as well pending https://github.com/llvm/llvm-project/pull/96561.

https://github.com/llvm/llvm-project/pull/98421