[clang] [clang] fix broken canonicalization of DeducedTemplateSpecializationType (PR #95202)

[Chuanqi Xu via cfe-commits]

ChuanqiXu9 wrote:

> It still fixes the original bug report though.

Yeah, this is why it is good.

> 
> Otherwise adding a test which directly tests all observable effects of the profiling fix would be a bit arbitrary, as we don't have any unit tests for the gazillion ways this could go wrong for the other AST nodes.

I don't understand this. If we can have a reduced test for this, why is it not great? 

> 
> This usually gets caught incidentally in diagnostics for unrelated tests. In this case that incidental test was in libc++.

Or, are you saying it is too hard to get reduced?


https://github.com/llvm/llvm-project/pull/95202