Make new Harmony constructors subclassing-friendly

src/collection.js

Index: src/collection.js
diff --git a/src/collection.js b/src/collection.js
index 01537e87b0973cee8a65fc759c17fad43fbf7387..deb1a8d902a2dfcbeb97c4902aa10139c233127d 100644
--- a/src/collection.js
+++ b/src/collection.js
@@ -44,11 +44,7 @@ var undefined_sentinel = {};
 // Harmony Set
 
 function SetConstructor() {
-  if (%_IsConstructCall()) {
-    %SetInitialize(this);
-  } else {
-    throw MakeTypeError('constructor_not_function', ['Set']);
-  }
+  %SetInitialize(this);
 }
 
 
@@ -108,7 +104,7 @@ function SetClear() {
                         ['Set.prototype.clear', this]);
   }
   // Replace the internal table with a new empty table.
-  %SetInitialize(this);
+  %SetClear(this);
 }
 
 
@@ -138,11 +134,7 @@ SetUpSet();
 // Harmony Map
 
 function MapConstructor() {
-  if (%_IsConstructCall()) {
-    %MapInitialize(this);
-  } else {
-    throw MakeTypeError('constructor_not_function', ['Map']);
-  }
+  %MapInitialize(this);
 }
 
 
@@ -209,7 +201,7 @@ function MapClear() {
                         ['Map.prototype.clear', this]);
   }
   // Replace the internal table with a new empty table.
-  %MapInitialize(this);
+  %MapClear(this);
 }
 
 
@@ -240,11 +232,7 @@ SetUpMap();
 // Harmony WeakMap
 
 function WeakMapConstructor() {
-  if (%_IsConstructCall()) {
-    %WeakCollectionInitialize(this);
-  } else {
-    throw MakeTypeError('constructor_not_function', ['WeakMap']);
-  }
+  %WeakMapInitialize(this);
 }
 
 
@@ -302,7 +290,7 @@ function WeakMapClear() {
                         ['WeakMap.prototype.clear', this]);
   }
   // Replace the internal table with a new empty table.
-  %WeakCollectionInitialize(this);
+  %WeakCollectionClear(this);
 }
 
 
@@ -332,11 +320,7 @@ SetUpWeakMap();
 // Harmony WeakSet
 
 function WeakSetConstructor() {
-  if (%_IsConstructCall()) {
-    %WeakCollectionInitialize(this);
-  } else {
-    throw MakeTypeError('constructor_not_function', ['WeakSet']);
-  }
+  %WeakSetInitialize(this);
 }
 
 
@@ -382,7 +366,7 @@ function WeakSetClear() {
                         ['WeakSet.prototype.clear', this]);
   }
   // Replace the internal table with a new empty table.
-  %WeakCollectionInitialize(this);
+  %WeakCollectionClear(this);
 }