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

test/cctest/test-api.cc

Index: test/cctest/test-api.cc
diff --git a/test/cctest/test-api.cc b/test/cctest/test-api.cc
index 9b12282954f9f14ac9a5e630d2b512d00f80029d..3a80397e7db4e4934f65e9a3122fff5c2ea84c26 100644
--- a/test/cctest/test-api.cc
+++ b/test/cctest/test-api.cc
@@ -9795,8 +9795,8 @@ THREADED_TEST(ConstructorForObject) {
     value = instance->CallAsConstructor(1, args);
     CHECK(try_catch.HasCaught());
     String::Utf8Value exception_value2(try_catch.Exception());
-    CHECK_EQ(
-        0, strcmp("TypeError: #<Object> is not a function", *exception_value2));
+    CHECK_EQ(0,
+             strcmp("TypeError: object is not a function", *exception_value2));
     try_catch.Reset();
   }
 
@@ -10165,8 +10165,8 @@ THREADED_TEST(CallAsFunction) {
     CHECK(value.IsEmpty());
     CHECK(try_catch.HasCaught());
     String::Utf8Value exception_value2(try_catch.Exception());
-    CHECK_EQ(0, strcmp("TypeError: [object Object] is not a function",
-                       *exception_value2));
+    CHECK_EQ(0,
+             strcmp("TypeError: object is not a function", *exception_value2));
     try_catch.Reset();
   }