[clang] [coroutines] Introduce [[clang::coro_not_lifetimebound]] (PR #76818)

[Ilya Biryukov via cfe-commits]

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@@ -1121,6 +1121,14 @@ def CoroLifetimeBound : InheritableAttr {
   let SimpleHandler = 1;
 }
 
+def CoroNotLifetimeBound : InheritableAttr {
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ilya-biryukov wrote:

Any alternatives to this name? Maybe `coro_disable_lifetime_bound`?

The current name confused me a little because `coro_lifetime_bound` is supposed to be applied to types so I naturally expect `coro_not_lifetime_bound` to be applied to types too. In practice, it's applied to functions so having a different name would help me avoid confusion.

WDYT?

https://github.com/llvm/llvm-project/pull/76818