[clang] [clang][Sema] support block pointers as non-type template parameters (PR #191694)

[via cfe-commits]

Serosh-commits wrote:

@mizvekov i will also add a codegen test and also this one too https://github.com/llvm/llvm-project/pull/190377#discussion_r3033821827

https://github.com/llvm/llvm-project/pull/191694