[es6] Initial steps towards a correct implementation of IsCallable.

src/objects-debug.cc

Index: src/objects-debug.cc
diff --git a/src/objects-debug.cc b/src/objects-debug.cc
index 961ad51f61bd9a05407a3b39914f15d9e8fba740..df9045b3f036de6c3b0d83ee0de0cb21273349b5 100644
--- a/src/objects-debug.cc
+++ b/src/objects-debug.cc
@@ -36,6 +36,7 @@ void Object::VerifyPointer(Object* p) {
 
 void Smi::SmiVerify() {
   CHECK(IsSmi());
+  CHECK(!IsCallable());

[rossberg, 2015/08/26 12:55:48]

Do we want to check this condition in more cases?

[Benedikt Meurer, 2015/08/27 05:18:23]

Don't know, but doable if you want, yeah.

 }
 
 
@@ -531,6 +532,7 @@ void JSFunction::JSFunctionVerify() {
   CHECK(next_function_link() == NULL ||
         next_function_link()->IsUndefined() ||
         next_function_link()->IsJSFunction());
+  CHECK(map()->is_callable());
 }
 
 
@@ -809,6 +811,7 @@ void JSFunctionProxy::JSFunctionProxyVerify() {
   JSProxyVerify();
   VerifyPointer(call_trap());
   VerifyPointer(construct_trap());
+  CHECK(map()->is_callable());
 }