[llvm] [LangRef] Cap maximum value of vscale at 2^31-1. (PR #144607)

[Ramkumar Ramachandra via llvm-commits]

https://github.com/artagnon commented:

I'm with @paulwalker-arm here: not sure why we should limit vscale values in the LangRef.

https://github.com/llvm/llvm-project/pull/144607