[llvm] [TableGen][Docs] Fix productionlists for assert and dump (PR #123739)

[Jay Foad via llvm-commits]

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@@ -1302,7 +1302,7 @@ output. It is intended for debugging purpose.
   instantiation point of the containing record.
 
 .. productionlist::
-   Dump: "dump"  `string` ";"
+   Dump: "dump" `Value` ";"
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jayfoad wrote:

Instead of changing that description, I added a note below explaining that the `Value` is the string. This is similar to how `assert` is documented. What do you think?

https://github.com/llvm/llvm-project/pull/123739