[clang] [Serialization] Load Specializations Lazily (PR #76774)

[Chuanqi Xu via cfe-commits]

ChuanqiXu9 wrote:

Oh, I didn't notice you've removed D153003 already. But the branch name looks not good. So I've created a pr in https://github.com/llvm/llvm-project/pull/83108

https://github.com/llvm/llvm-project/pull/76774