[ADT] Add DenseMap::insert_range (#133600)

This PR add `DenseMap::insert_range` to `DenseMap` for consistency with
existing `DenseSet::insert_range`, `SmallSet::insert_range` and
`std::map::insert_range`.

llvm/include/llvm/ADT/DenseMap.h

@@ -14,6 +14,7 @@
 #ifndef LLVM_ADT_DENSEMAP_H
 #define LLVM_ADT_DENSEMAP_H
 
+#include "llvm/ADT/ADL.h"
 #include "llvm/ADT/DenseMapInfo.h"
 #include "llvm/ADT/EpochTracker.h"
 #include "llvm/Support/AlignOf.h"
@@ -302,6 +303,11 @@ public:
       insert(*I);
   }
 
+  /// Inserts range of 'std::pair<KeyT, ValueT>' values into the map.
+  template <typename Range> void insert_range(Range &&R) {
+    insert(adl_begin(R), adl_end(R));
+  }
+
   template <typename V>
   std::pair<iterator, bool> insert_or_assign(const KeyT &Key, V &&Val) {
     auto Ret = try_emplace(Key, std::forward<V>(Val));

llvm/unittests/ADT/DenseMapTest.cpp

@@ -379,6 +379,28 @@ TEST(DenseMapCustomTest, EqualityComparison) {
   EXPECT_NE(M1, M3);
 }
 
+TEST(DenseMapCustomTest, InsertRange) {
+  DenseMap<int, int> M;
+
+  std::pair<int, int> InputVals[3] = {{0, 0}, {0, 1}, {1, 2}};
+  M.insert_range(InputVals);
+
+  EXPECT_EQ(M.size(), 2u);
+  EXPECT_THAT(M, testing::UnorderedElementsAre(testing::Pair(0, 0),
+                                               testing::Pair(1, 2)));
+}
+
+TEST(SmallDenseMapCustomTest, InsertRange) {
+  SmallDenseMap<int, int> M;
+
+  std::pair<int, int> InputVals[3] = {{0, 0}, {0, 1}, {1, 2}};
+  M.insert_range(InputVals);
+
+  EXPECT_EQ(M.size(), 2u);
+  EXPECT_THAT(M, testing::UnorderedElementsAre(testing::Pair(0, 0),
+                                               testing::Pair(1, 2)));
+}
+
 // Test for the default minimum size of a DenseMap
 TEST(DenseMapCustomTest, DefaultMinReservedSizeTest) {
   // IF THIS VALUE CHANGE, please update InitialSizeTest, InitFromIterator, and

llvm/unittests/ADT/DenseSetTest.cpp

@@ -58,6 +58,13 @@ TEST(DenseSetTest, InsertRange) {
   EXPECT_THAT(set, ::testing::UnorderedElementsAre(1, 2, 3));
 }
 
+TEST(SmallDenseSetTest, InsertRange) {
+  llvm::SmallDenseSet<unsigned> set;
+  constexpr unsigned Args[] = {9, 7, 8};
+  set.insert_range(Args);
+  EXPECT_THAT(set, ::testing::UnorderedElementsAre(7, 8, 9));
+}
+
 struct TestDenseSetInfo {
   static inline unsigned getEmptyKey() { return ~0; }
   static inline unsigned getTombstoneKey() { return ~0U - 1; }