[llvm-branch-commits] [NFC][Loop] Remove unused verbose loop debug output (PR #192830)

[Aiden Grossman via llvm-branch-commits]

https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/192830

This has been defined out using the preprocessor for ~14 years. Given it
doesn't look like it has gotten any use since then, just remove it to
clean the code up a bit.