Start migrating error message templates to the runtime.

src/weak-collection.js

Index: src/weak-collection.js
diff --git a/src/weak-collection.js b/src/weak-collection.js
index 4244792816abbda6a29d34df6d82b8ce86a8a2b8..233f9783841ffa9c39a46b6037f52a0d7e319cd7 100644
--- a/src/weak-collection.js
+++ b/src/weak-collection.js
@@ -25,7 +25,7 @@ function WeakMapConstructor(iterable) {
   if (!IS_NULL_OR_UNDEFINED(iterable)) {
     var adder = this.set;
     if (!IS_SPEC_FUNCTION(adder)) {
-      throw MakeTypeError('property_not_function', ['set', this]);
+      throw MakeTypeError(kPropertyNotFunction, ['set', this]);
     }
     for (var nextItem of iterable) {
       if (!IS_SPEC_OBJECT(nextItem)) {
@@ -116,7 +116,7 @@ function WeakSetConstructor(iterable) {
   if (!IS_NULL_OR_UNDEFINED(iterable)) {
     var adder = this.add;
     if (!IS_SPEC_FUNCTION(adder)) {
-      throw MakeTypeError('property_not_function', ['add', this]);
+      throw MakeTypeError(kPropertyNotFunction, ['add', this]);
     }
     for (var value of iterable) {
       %_CallFunction(this, value, adder);