Skip expensive hasInstance() type-checks in overloads

Source/bindings/scripts/v8_interface.py

Index: Source/bindings/scripts/v8_interface.py
diff --git a/Source/bindings/scripts/v8_interface.py b/Source/bindings/scripts/v8_interface.py
index 9cb32a59af27c5984346bf23bf7c82a820cc6830..50e9bc12c07c415613f8cc72efb7120997f29489 100644
--- a/Source/bindings/scripts/v8_interface.py
+++ b/Source/bindings/scripts/v8_interface.py
@@ -688,7 +688,7 @@ def resolution_tests_methods(effective_overloads):
                for effective_overload in effective_overloads]
     if len(methods) == 1:
         # If only one method with a given length, no test needed
-        yield 'true', methods[0]
+        yield 'true', methods[0], -1
         return
 
     # 6. If there is more than one entry in S, then set d to be the
@@ -710,6 +710,9 @@ def resolution_tests_methods(effective_overloads):
     idl_types = [argument['idl_type_object'] for argument in arguments]
     idl_types_methods = zip(idl_types, methods)
 
+    for argument in arguments:
+        argument['is_ever_distinguishing_argument'] = True
+
     # We can’t do a single loop through all methods or simply sort them, because
     # a method may be listed in multiple steps of the resolution algorithm, and
     # which test to apply differs depending on the step.
@@ -725,7 +728,7 @@ def resolution_tests_methods(effective_overloads):
         method = next(method for argument, method in arguments_methods
                       if argument['is_optional'])
         test = '%s->IsUndefined()' % cpp_value
-        yield test, method
+        yield test, method, -1
     except StopIteration:
         pass
 
@@ -736,7 +739,7 @@ def resolution_tests_methods(effective_overloads):
         method = next(method for idl_type, method in idl_types_methods
                       if idl_type.is_nullable)
         test = 'isUndefinedOrNull(%s)' % cpp_value
-        yield test, method
+        yield test, method, -1
     except StopIteration:
         pass
 
@@ -751,7 +754,7 @@ def resolution_tests_methods(effective_overloads):
                              for idl_type, method in idl_types_methods
                              if idl_type.is_wrapper_type):
         test = 'V8{idl_type}::hasInstance({cpp_value}, info.GetIsolate())'.format(idl_type=idl_type.base_type, cpp_value=cpp_value)
-        yield test, method
+        yield test, method, index
 
     # 8. Otherwise: if V is any kind of object except for a native Date object,
     # a native RegExp object, and there is an entry in S that has one of the
@@ -773,13 +776,13 @@ def resolution_tests_methods(effective_overloads):
             # (We test for Array instead of generic Object to type-check.)
             # FIXME: test for Object during resolution, then have type check for
             # Array in overloaded method: http://crbug.com/262383
-            yield '%s->IsArray()' % cpp_value, method
+            yield '%s->IsArray()' % cpp_value, method, index
     for idl_type, method in idl_types_methods:
         if idl_type.is_dictionary or idl_type.name == 'Dictionary':
             # FIXME: should be '{1}->IsObject() && !{1}->IsDate() && !{1}->IsRegExp()'.format(cpp_value)
             # FIXME: the IsDate and IsRegExp checks can be skipped if we've
             # already generated tests for them.
-            yield '%s->IsObject()' % cpp_value, method
+            yield '%s->IsObject()' % cpp_value, method, index
 
     # (Check for exact type matches before performing automatic type conversion;
     # only needed if distinguishing between primitive types.)
@@ -795,7 +798,7 @@ def resolution_tests_methods(effective_overloads):
                 method = next(method for idl_type, method in idl_types_methods
                               if idl_type.is_numeric_type)
                 test = '%s->IsNumber()' % cpp_value
-                yield test, method
+                yield test, method, index
             except StopIteration:
                 pass
 
@@ -813,7 +816,7 @@ def resolution_tests_methods(effective_overloads):
     try:
         method = next(method for idl_type, method in idl_types_methods
                       if idl_type.is_string_type or idl_type.is_enum)
-        yield 'true', method
+        yield 'true', method, -1
     except StopIteration:
         pass
 
@@ -823,7 +826,7 @@ def resolution_tests_methods(effective_overloads):
     try:
         method = next(method for idl_type, method in idl_types_methods
                       if idl_type.is_numeric_type)
-        yield 'true', method
+        yield 'true', method, -1
     except StopIteration:
         pass