add maps and sets to zone containers

R=bmeurer@chromium.org

BUG=

Review URL: https://codereview.chromium.org/889963002

Cr-Commit-Position: refs/heads/master@{#26370}

src/compiler/register-allocator-verifier.cc

@@ -240,13 +240,9 @@ struct PhiData : public ZoneObject {
   IntVector operands;
 };
 
-typedef std::map<int, PhiData*, std::less<int>,
-                 zone_allocator<std::pair<int, PhiData*>>> PhiMapBase;
-
-class PhiMap : public PhiMapBase, public ZoneObject {
+class PhiMap : public ZoneMap<int, PhiData*>, public ZoneObject {
  public:
-  explicit PhiMap(Zone* zone)
-      : PhiMapBase(key_compare(), allocator_type(zone)) {}
+  explicit PhiMap(Zone* zone) : ZoneMap<int, PhiData*>(zone) {}
 };
 
 struct OperandLess {
@@ -271,13 +267,11 @@ class OperandMap : public ZoneObject {
     int succ_vreg;       // valid if propagated back from successor block.
   };
 
-  typedef std::map<
-      const InstructionOperand*, MapValue*, OperandLess,
-      zone_allocator<std::pair<const InstructionOperand*, MapValue*>>> MapBase;
-
-  class Map : public MapBase {
+  class Map
+      : public ZoneMap<const InstructionOperand*, MapValue*, OperandLess> {
    public:
-    explicit Map(Zone* zone) : MapBase(key_compare(), allocator_type(zone)) {}
+    explicit Map(Zone* zone)
+        : ZoneMap<const InstructionOperand*, MapValue*, OperandLess>(zone) {}
 
     // Remove all entries with keys not in other.
     void Intersect(const Map& other) {

src/zone-containers.h

@@ -7,7 +7,9 @@
 
 #include <deque>
 #include <list>
+#include <map>
 #include <queue>
+#include <set>
 #include <stack>
 #include <vector>
 
@@ -83,6 +85,31 @@ class ZoneStack : public std::stack<T, ZoneDeque<T>> {
 };
 
 
+// A wrapper subclass for std::set to make it easy to construct one that uses
+// a zone allocator.
+template <typename K, typename Compare = std::less<K>>
+class ZoneSet : public std::set<K, Compare, zone_allocator<K>> {
+ public:
+  // Constructs an empty set.
+  explicit ZoneSet(Zone* zone)
+      : std::set<K, Compare, zone_allocator<K>>(Compare(),
+                                                zone_allocator<K>(zone)) {}
+};
+
+
+// A wrapper subclass for std::map to make it easy to construct one that uses
+// a zone allocator.
+template <typename K, typename V, typename Compare = std::less<K>>
+class ZoneMap
+    : public std::map<K, V, Compare, zone_allocator<std::pair<K, V>>> {
+ public:
+  // Constructs an empty map.
+  explicit ZoneMap(Zone* zone)
+      : std::map<K, V, Compare, zone_allocator<std::pair<K, V>>>(
+            Compare(), zone_allocator<std::pair<K, V>>(zone)) {}
+};
+
+
 // Typedefs to shorten commonly used vectors.
 typedef ZoneVector<bool> BoolVector;
 typedef ZoneVector<int> IntVector;