[llvm] [TLI] Use the VFABI demangling when declaring vector variants. (PR #76753)

[Paschalis Mpeis via llvm-commits]

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@@ -35,35 +35,36 @@ STATISTIC(NumCompUsedAdded,
 
 /// A helper function that adds the vector function declaration that
 /// vectorizes the CallInst CI with a vectorization factor of VF
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paschalis-mpeis wrote:

nit: could improve original doxygen comment with `\p CI` instead of `CI`.
Same for `VF`.

https://github.com/llvm/llvm-project/pull/76753