[llvm] [ADT] Use range-based for loops in SparseBitVector.h (NFC) (PR #158408)

[Shilei Tian via llvm-commits]

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@@ -799,11 +799,8 @@ class SparseBitVector {
 
   unsigned count() const {
     unsigned BitCount = 0;
-    for (ElementListConstIter Iter = Elements.begin();
-         Iter != Elements.end();
-         ++Iter)
-      BitCount += Iter->count();
-
+    for (const auto &Elem : Elements)
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shiltian wrote:

no auto?

https://github.com/llvm/llvm-project/pull/158408