[clang] [clang][ThreadSafety] Enable late parse for all capabilities, under the experimental flag (PR #212615)

[Jameson Nash via cfe-commits]

vtjnash wrote:

Yes, concretely it was driven by encountering this pattern in the linux kernel source code here, so it would require this PR to be able to annotate that function definition correctly:

https://github.com/torvalds/linux/blob/fc02acf6ac0ccde0c805c2daa9148683cdd01ba8/include/linux/kref.h#L103-L105

Abstractly, the incentive was that a program's API and ABI shouldn't be driven by the need of the clang to parse them correctly--that's why C has forward references in the first place.

https://github.com/llvm/llvm-project/pull/212615