Use a SmallVector to reduce heap traffic. This speeds up bcreader 10%

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34231 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Bytecode/Reader/Reader.h

@@ -80,7 +80,7 @@ public:
   /// globals section.
   /// @brief A list of values as a User of those Values.
   class ValueList : public User {
-    std::vector<Use> Uses;
+    SmallVector<Use, 32> Uses;
   public:
     ValueList() : User(Type::VoidTy, Value::ArgumentVal, 0, 0) {}