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

src/array.js

Index: src/array.js
diff --git a/src/array.js b/src/array.js
index af3dbd701ebac2f756dde8ff379af2c5efc9370c..5c74b7f8198ab8fcd9d548fd05260e6d251fc9e5 100644
--- a/src/array.js
+++ b/src/array.js
@@ -386,7 +386,7 @@ function ArrayToString() {
     array = TO_OBJECT(this);
     func = array.join;
   }
-  if (!IS_SPEC_FUNCTION(func)) {
+  if (!IS_CALLABLE(func)) {
     return %_CallFunction(array, ObjectToString);
   }
   return %_CallFunction(array, func);
@@ -903,7 +903,7 @@ function InnerArraySort(length, comparefn) {
   // In-place QuickSort algorithm.
   // For short (length <= 22) arrays, insertion sort is used for efficiency.
 
-  if (!IS_SPEC_FUNCTION(comparefn)) {
+  if (!IS_CALLABLE(comparefn)) {
     comparefn = function (x, y) {
       if (x === y) return 0;
       if (%_IsSmi(x) && %_IsSmi(y)) {
@@ -1195,7 +1195,7 @@ function ArraySort(comparefn) {
 // preserving the semantics, since the calls to the receiver function can add
 // or delete elements from the array.
 function InnerArrayFilter(f, receiver, array, length) {
-  if (!IS_SPEC_FUNCTION(f)) throw MakeTypeError(kCalledNonCallable, f);
+  if (!IS_CALLABLE(f)) throw MakeTypeError(kCalledNonCallable, f);
   var needs_wrapper = false;
   if (IS_NULL(receiver)) {
     if (%IsSloppyModeFunction(f)) receiver = UNDEFINED;
@@ -1235,7 +1235,7 @@ function ArrayFilter(f, receiver) {
 }
 
 function InnerArrayForEach(f, receiver, array, length) {
-  if (!IS_SPEC_FUNCTION(f)) throw MakeTypeError(kCalledNonCallable, f);
+  if (!IS_CALLABLE(f)) throw MakeTypeError(kCalledNonCallable, f);
   var needs_wrapper = false;
   if (IS_NULL(receiver)) {
     if (%IsSloppyModeFunction(f)) receiver = UNDEFINED;
@@ -1268,7 +1268,7 @@ function ArrayForEach(f, receiver) {
 
 
 function InnerArraySome(f, receiver, array, length) {
-  if (!IS_SPEC_FUNCTION(f)) throw MakeTypeError(kCalledNonCallable, f);
+  if (!IS_CALLABLE(f)) throw MakeTypeError(kCalledNonCallable, f);
   var needs_wrapper = false;
   if (IS_NULL(receiver)) {
     if (%IsSloppyModeFunction(f)) receiver = UNDEFINED;
@@ -1305,7 +1305,7 @@ function ArraySome(f, receiver) {
 
 
 function InnerArrayEvery(f, receiver, array, length) {
-  if (!IS_SPEC_FUNCTION(f)) throw MakeTypeError(kCalledNonCallable, f);
+  if (!IS_CALLABLE(f)) throw MakeTypeError(kCalledNonCallable, f);
   var needs_wrapper = false;
   if (IS_NULL(receiver)) {
     if (%IsSloppyModeFunction(f)) receiver = UNDEFINED;
@@ -1339,7 +1339,7 @@ function ArrayEvery(f, receiver) {
 
 
 function InnerArrayMap(f, receiver, array, length) {
-  if (!IS_SPEC_FUNCTION(f)) throw MakeTypeError(kCalledNonCallable, f);
+  if (!IS_CALLABLE(f)) throw MakeTypeError(kCalledNonCallable, f);
   var needs_wrapper = false;
   if (IS_NULL(receiver)) {
     if (%IsSloppyModeFunction(f)) receiver = UNDEFINED;
@@ -1503,7 +1503,7 @@ function ArrayLastIndexOf(element, index) {
 
 
 function InnerArrayReduce(callback, current, array, length, argumentsLength) {
-  if (!IS_SPEC_FUNCTION(callback)) {
+  if (!IS_CALLABLE(callback)) {
     throw MakeTypeError(kCalledNonCallable, callback);
   }
 
@@ -1546,7 +1546,7 @@ function ArrayReduce(callback, current) {
 
 function InnerArrayReduceRight(callback, current, array, length,
                                argumentsLength) {
-  if (!IS_SPEC_FUNCTION(callback)) {
+  if (!IS_CALLABLE(callback)) {
     throw MakeTypeError(kCalledNonCallable, callback);
   }