[TableGen] Fixes -Wrange-loop-analysis warnings

This avoids new warnings due to D68912 adds -Wrange-loop-analysis to -Wall.

Differential Revision: https://reviews.llvm.org/D71807
diff --git a/llvm/utils/TableGen/AsmMatcherEmitter.cpp b/llvm/utils/TableGen/AsmMatcherEmitter.cpp
index 1d39b30..ccf0959 100644
--- a/llvm/utils/TableGen/AsmMatcherEmitter.cpp
+++ b/llvm/utils/TableGen/AsmMatcherEmitter.cpp
@@ -3347,7 +3347,7 @@
       return true;
     if (A.size() > B.size())
       return false;
-    for (const auto &Pair : zip(A, B)) {
+    for (auto Pair : zip(A, B)) {
       if (std::get<0>(Pair)->getName() < std::get<1>(Pair)->getName())
         return true;
       if (std::get<0>(Pair)->getName() > std::get<1>(Pair)->getName())