[llvm] [AMDGPU][MC] Adding symbolic name for the constant 1 over 2*pi (PR #160617)

[Ivan Kosarev via llvm-commits]

kosarev wrote:

For what the change does, it seems a couple of `createConstantSymbol()` calls would suffice.

But as Stanislav said, having a proper universal designation for the inline constant looks more appealing.

https://github.com/llvm/llvm-project/pull/160617