[llvm] [SLP] Normalize debug messages for newTreeEntry. (PR #119514)

[Alexey Bataev via llvm-commits]

alexey-bataev wrote:

> > Would be useful to dump the list of scalars, if possible, helps in many cases
> 
> how about dump `TreeEntry` directly?

Sounds good

https://github.com/llvm/llvm-project/pull/119514