[llvm] Enable logf128 constant folding for hosts with 128bit long double (PR #104929)

[NAKAMURA Takumi via llvm-commits]

chapuni wrote:

@MDevereau Thanks. I am less happy with it but fair enough since it is configurable.

I think we need to discuss. Could you post a survey to the forum before it would be turned on, please?

https://github.com/llvm/llvm-project/pull/104929