[clang] [clang] Implement transforms for DeducedTemplateName (PR #108491)

[Alexander Kornienko via cfe-commits]

alexfh wrote:

I could reduce the code to something that compiles with Clang before fa6580470547411667b866362941db0b02e25578, but not after it, this PR doesn't fix the issue. The example is: https://gcc.godbolt.org/z/odWYhxGxK

Note that the code doesn't compile with Clang 18.1, but should compile with Clang 19 (which I couldn't find on Compiler Explorer) and for that matter with all Clang versions starting from b86e0992bfa6c58be077d82d824016f590ac5d90 and up to fa6580470547411667b866362941db0b02e25578.

https://github.com/llvm/llvm-project/pull/108491