IDL: Improve overload resolution for methods with variadic arguments

Source/bindings/scripts/v8_interface.py

 # Copyright (C) 2013 Google Inc. All rights reserved.
 # coding=utf-8
 #
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@@ skipping 618 matching lines @@
         # 1. Let n be the number of arguments X is declared to take.
         n = len(arguments)
         # 2. Let t0..n−1 be a list of types, where ti is the type of X’s
         # argument at index i.
         # (“type list”)
         t = tuple(argument['idl_type_object'] for argument in arguments)
         # 3. Let o0..n−1 be a list of optionality values, where oi is “variadic”
         # if X’s argument at index i is a final, variadic argument, “optional”
         # if the argument is optional, and “required” otherwise.
         # (“optionality list”)
-        # (We’re just using a boolean for optional vs. required.)
-        o = tuple(argument['is_optional'] for argument in arguments)
+        # (We’re just using a boolean for optional/variadic vs. required.)
+        o = tuple(argument['is_optional'] or argument['is_variadic']
+                  for argument in arguments)
         # 4. Add to S the tuple <X, t0..n−1, o0..n−1>.
         S.append((X, t, o))
         # 5. If X is declared to be variadic, then:
         # (Not used, so not implemented.)
         # 6. Initialize i to n−1.
         i = n - 1
         # 7. While i ≥ 0:
         # Spec bug (fencepost error); should be “While i > 0:”
         # https://www.w3.org/Bugs/Public/show_bug.cgi?id=25590
         while i > 0:
@@ skipping 588 matching lines @@
         deleter = next(
             method
             for method in interface.operations
             if ('deleter' in method.specials and
                 len(method.arguments) == 1 and
                 str(method.arguments[0].idl_type) == 'DOMString'))
     except StopIteration:
         return None
 
     return property_deleter(deleter)