[clang] [clang] [Serialization] Introduce noload_redecls (PR #170823)

[Alexander Kornienko via cfe-commits]

alexfh wrote:

I ran a build of all of our code with the assertions-enabled clang. So far I'm seeing compilation timeouts on a large number of compilations. I'm trying to figure out whether this is an infinite loop or a superlinear algorithm.

https://github.com/llvm/llvm-project/pull/170823