[clang] llvm-canon (PR #68176)

[Puyan Lotfi via cfe-commits]

plotfi wrote:

> Please don't use the term canon/canonicalize for this pass or tool. LLVM has an existing notion of "canonicalization" which does not coincide with what is being done here.

The term comes from an older pass that did similar algorithms on MIR. They are only borrowing the term from it. 

https://github.com/llvm/llvm-project/pull/68176