[llvm] [NFC][LLVM][CodeGen] Refactor MIR Printer (PR #137361)

[Rahul Joshi via llvm-commits]

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@@ -537,6 +537,9 @@ class ListSeparator {
     }
     return Separator;
   }
+
+  // Enables the use of same ListSeparator object for multiple lists.
+  void reset() { First = true; }
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jurahul wrote:

Done.

https://github.com/llvm/llvm-project/pull/137361