[clang] [clang][CodeGen] Omit pre-opt link when post-opt is link requested (PR #85672)

[via cfe-commits]

b-sumner wrote:

> Currently if a user doesn't supply the new "-link-builtin-bitcodes-postopt" option, linking builtin bitcodes happens first, then the optimization pipeline follows. Does that cover the case you're talking about?

I'm thinking of an option that developers can use.  If -link-builtin-bitcodes-postopt, becomes the default, how can developers disable it?

https://github.com/llvm/llvm-project/pull/85672