[llvm] [LIT] Fix env without subcommand causing early return in pipeline (PR #184028)

[James Henderson via llvm-commits]

jh7370 wrote:

> > Hi @jh7370, thanks for the review!
> > 
> > 1. I wrote the PR description manually but used AI to tweak the grammar and spelling. I usually use the Why/How/What structure because I find it clear and review-friendly. Thanks for the reminder-- I will keep it shorter and more concise in future PRs.
> 
> Please edit the PR description to be more appropriate. Typically line length <72 chars, and only minimal formatting is very helpful, so that the commit log is easy to read from the command line or in an editor.

@ilovepi / @nailo2c, there's no need to manually wrap PR descriptions: when they're converted to commit messages, GitHub should automatically convert the paragraphs into 72-character wrapped lines in the final message, so that they properly wrap in git log. In fact, doing it by hand inhibits GitHub from automatically unwrapping lines at that boundary, when viewed in the GitHub UI, assuming you don't wrap at exactly the right character count.

https://github.com/llvm/llvm-project/pull/184028