[clang] [clang] Introduce [[clang::lifetime_capture_by(X)]] (PR #111499)

[Haojian Wu via cfe-commits]

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@@ -3967,6 +3967,80 @@ Attribute ``trivial_abi`` has no effect in the following cases:
   }];
 }
 
+
+def LifetimeCaptureByDocs : Documentation {
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hokein wrote:

nit: let's move this section immediately right after the `LifetimeboundDocs`.

https://github.com/llvm/llvm-project/pull/111499