[ADT] Remove ImmutableSet::foreach and ImmutableMap::foreach (NFC)

These functions seem to be unused for at least 1 year.

llvm/include/llvm/ADT/ImmutableMap.h

@@ -140,44 +140,7 @@ public:
 
   bool isEmpty() const { return !Root; }
 
-  //===--------------------------------------------------===//
-  // Foreach - A limited form of map iteration.
-  //===--------------------------------------------------===//
-
-private:
-  template <typename Callback>
-  struct CBWrapper {
-    Callback C;
-
-    void operator()(value_type_ref V) { C(V.first,V.second); }
-  };
-
-  template <typename Callback>
-  struct CBWrapperRef {
-    Callback &C;
-
-    CBWrapperRef(Callback& c) : C(c) {}
-
-    void operator()(value_type_ref V) { C(V.first,V.second); }
-  };
-
 public:
-  template <typename Callback>
-  void foreach(Callback& C) {
-    if (Root) {
-      CBWrapperRef<Callback> CB(C);
-      Root->foreach(CB);
-    }
-  }
-
-  template <typename Callback>
-  void foreach() {
-    if (Root) {
-      CBWrapper<Callback> CB;
-      Root->foreach(CB);
-    }
-  }
-
   //===--------------------------------------------------===//
   // For testing.
   //===--------------------------------------------------===//

llvm/include/llvm/ADT/ImmutableSet.h

@@ -169,20 +169,6 @@ public:
   ///  is logarithmic in the size of the tree.
   bool contains(key_type_ref K) { return (bool) find(K); }
 
-  /// foreach - A member template the accepts invokes operator() on a functor
-  ///  object (specified by Callback) for every node/subtree in the tree.
-  ///  Nodes are visited using an inorder traversal.
-  template <typename Callback>
-  void foreach(Callback& C) {
-    if (ImutAVLTree* L = getLeft())
-      L->foreach(C);
-
-    C(value);
-
-    if (ImutAVLTree* R = getRight())
-      R->foreach(C);
-  }
-
   /// validateTree - A utility method that checks that the balancing and
   ///  ordering invariants of the tree are satisfied.  It is a recursive
   ///  method that returns the height of the tree, which is then consumed
@@ -1063,12 +1049,6 @@ public:
   ///   This method runs in constant time.
   bool isSingleton() const { return getHeight() == 1; }
 
-  template <typename Callback>
-  void foreach(Callback& C) { if (Root) Root->foreach(C); }
-
-  template <typename Callback>
-  void foreach() { if (Root) { Callback C; Root->foreach(C); } }
-
   //===--------------------------------------------------===//
   // Iterators.
   //===--------------------------------------------------===//

llvm/unittests/ADT/ImmutableSetTest.cpp

@@ -136,41 +136,6 @@ TEST_F(ImmutableSetTest, RemoveIntSetTest) {
   EXPECT_TRUE(S4.contains(5));
 }
 
-TEST_F(ImmutableSetTest, CallbackCharSetTest) {
-  ImmutableSet<char>::Factory f;
-  ImmutableSet<char> S = f.getEmptySet();
-
-  ImmutableSet<char> S2 = f.add(f.add(f.add(S, 'a'), 'e'), 'i');
-  ImmutableSet<char> S3 = f.add(f.add(S2, 'o'), 'u');
-
-  S3.foreach<MyIter>();
-
-  ASSERT_STREQ("aeiou", buffer);
-}
-
-TEST_F(ImmutableSetTest, Callback2CharSetTest) {
-  ImmutableSet<char>::Factory f;
-  ImmutableSet<char> S = f.getEmptySet();
-
-  ImmutableSet<char> S2 = f.add(f.add(f.add(S, 'b'), 'c'), 'd');
-  ImmutableSet<char> S3 = f.add(f.add(f.add(S2, 'f'), 'g'), 'h');
-
-  MyIter obj;
-  S3.foreach<MyIter>(obj);
-  ASSERT_STREQ("bcdfgh", buffer);
-  ASSERT_EQ(6, obj.counter);
-
-  MyIter obj2;
-  S2.foreach<MyIter>(obj2);
-  ASSERT_STREQ("bcd", buffer);
-  ASSERT_EQ(3, obj2.counter);
-
-  MyIter obj3;
-  S.foreach<MyIter>(obj);
-  ASSERT_STREQ("", buffer);
-  ASSERT_EQ(0, obj3.counter);
-}
-
 TEST_F(ImmutableSetTest, IterLongSetTest) {
   ImmutableSet<long>::Factory f;
   ImmutableSet<long> S = f.getEmptySet();