[clang] [NFC][analyzer] Clean up obsolete installation instructions (PR #166193)

[Donát Nagy via cfe-commits]

NagyDonat wrote:

@steakhal I re-added some references to the availability of `scan-build` and `scan-view` (in the command-line usage page where the role of `scan-build` is described). I admit that this is a bit barebones, but not worse than the situation before this PR and I don't know much about these tools, so I cannot easily add more information.

> Also, I believe that having a quick setup for a common vendor is useful, such as for Debian.

True, but I think this is unrelated to this PR. There wasn't such setup guide in the file removed by this PR and I don't have capacity to add it right now. (I only mentioned Debian because apparently Debian had provided some documentation/manpage for the script `scan-view` which is undocumented within LLVM/clang itself.)


https://github.com/llvm/llvm-project/pull/166193