[llvm] [IR] Allow nofree on return values (PR #203491)

[Nikita Popov via llvm-commits]

nikic wrote:

> I don't think it's a good idea to have an attribute which is both a return attribute, and a function attribute, with different meanings. They technically don't conflict because they're in different positions, but it seems very easy to confuse them in textual IR.

Okay, I've put up an alternative PR at https://github.com/llvm/llvm-project/pull/206445, which adds `nofreeobj` instead. (The semantics between argument and return attribute still differ, but I think only in the obvious way...)

https://github.com/llvm/llvm-project/pull/203491