[clang] [clang] Enable C++17 relaxed template template argument matching by default (PR #89807)

[via cfe-commits]

cor3ntin wrote:

@joanahalili 
> We are seeing a widespread breakage due to this commit and could use having the flag -fno-relaxed-template-template-args un-deprecated for a while. This would help do a cleanup on our end.

Can you provide more information? How widespread are we talking about? You have example of common breakages?
Thanks

https://github.com/llvm/llvm-project/pull/89807