Use ranges to concisely express iteration

No functional change is intended, this should just clean things up a
little.

llvm-svn: 273522
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 790ff4c..5761ece 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -8770,12 +8770,11 @@
       Self.ModAsSideEffect = &ModAsSideEffect;
     }
     ~SequencedSubexpression() {
-      for (auto MI = ModAsSideEffect.rbegin(), ME = ModAsSideEffect.rend();
-           MI != ME; ++MI) {
-        UsageInfo &U = Self.UsageMap[MI->first];
+      for (auto &M : llvm::reverse(ModAsSideEffect)) {
+        UsageInfo &U = Self.UsageMap[M.first];
         auto &SideEffectUsage = U.Uses[UK_ModAsSideEffect];
-        Self.addUsage(U, MI->first, SideEffectUsage.Use, UK_ModAsValue);
-        SideEffectUsage = MI->second;
+        Self.addUsage(U, M.first, SideEffectUsage.Use, UK_ModAsValue);
+        SideEffectUsage = M.second;
       }
       Self.ModAsSideEffect = OldModAsSideEffect;
     }