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

[Alexander Kornienko via cfe-commits]

alexfh wrote:

Unfortunately, the original code, from which I reduced the test case for this, still breaks (without crashing Clang though). I'm trying to come up with another test case now.

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