[llvm] [NFC][TableGen] Use StringRef in X86RecognizableInstr (PR #139648)

[Rahul Joshi via llvm-commits]

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@@ -336,12 +336,13 @@ class RecognizableInstr : public RecognizableInstrBase {
   /// @param operandMapping       - The operand mapping, which has an entry for
   ///                               each operand that indicates whether it is a
   ///                               duplicate, and of what.
+  using encodingFn =
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jurahul wrote:

Done

https://github.com/llvm/llvm-project/pull/139648