Introduce a range version of std::find, and use in SCEV

[dblaikie]

Looks good, please commit.

(one day we'll probably want to generalize these a bit further so they handle arbitrary ranges using ADL-calls to begin/end ("using std::begin; ... begin(x)") so they work with arrays, for example)

llvm/trunk/include/llvm/ADT/STLExtras.h

 /// Provide wrappers to std::any_of which take ranges instead of having to pass
 /// begin/end explicitly.
 template <typename R, class UnaryPredicate>
 bool any_of(R &&Range, UnaryPredicate &&P) {
   return std::any_of(Range.begin(), Range.end(),
                      std::forward<UnaryPredicate>(P));
 }
 
+/// Provide wrappers to std::find which take ranges instead of having to pass
+/// begin/end explicitly.
+template<typename R, class T>
+auto find(R &&Range, const T &val) -> decltype(Range.begin()) {
+  return std::find(Range.begin(), Range.end(), val);
+}
+
 //===----------------------------------------------------------------------===//
 //     Extra additions to <memory>
 //===----------------------------------------------------------------------===//
 
 // Implement make_unique according to N3656.
 
 /// \brief Constructs a `new T()` with the given args and returns a
 ///        `unique_ptr<T>` which owns the object.

llvm/trunk/lib/Analysis/ScalarEvolution.cpp

 
 /// Is MaybeMaxExpr an SMax or UMax of Candidate and some other values?
 template<typename MaxExprType>
 static bool IsMaxConsistingOf(const SCEV *MaybeMaxExpr,
                               const SCEV *Candidate) {
   const MaxExprType *MaxExpr = dyn_cast<MaxExprType>(MaybeMaxExpr);
   if (!MaxExpr) return false;
 
-  auto It = std::find(MaxExpr->op_begin(), MaxExpr->op_end(), Candidate);
-  return It != MaxExpr->op_end();
+  return find(MaxExpr->operands(), Candidate) != MaxExpr->op_end();
 }
 
 
 /// Is MaybeMinExpr an SMin or UMin of Candidate and some other values?
 template<typename MaxExprType>
 static bool IsMinConsistingOf(ScalarEvolution &SE,
                               const SCEV *MaybeMinExpr,
                               const SCEV *Candidate) {