[llvm] [LangRef] Clarify definition of fragments (PR #145582)

[Orlando Cazalet-Hyams via llvm-commits]

https://github.com/OCHyams approved this pull request.

Thanks, this LGTM! Perhaps best to wait a day or two to see if anyone else has comments on the wording

https://github.com/llvm/llvm-project/pull/145582