[llvm] [LLVM][NVPTX]: Add intrinsic for setmaxnreg (PR #77289)

[Durgadoss R via llvm-commits]

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+//===--- NVVMIntrinsicFlags.h -----------------------------------*- C++ -*-===//
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durga4github wrote:

I could not find exact precedents.

As I mentioned in the commit message, we would like to use these enums/flags even in upstream clients (i.e. producers of the intrinsic like NVVM Dialect for example) and not just in the NVPTX backend.  So, I tried to choose a location that looks relevant/compatible both upstream and downstream.

With that, I found a few *Metadata.h, *Attributes.h files in this directory and thought it might be an appropriate one. But, I am open to other preferences that we may have.

https://github.com/llvm/llvm-project/pull/77289