Revert "Make toLocaleString on arrays always call toLocaleString on its elements."

This reverts commit 457c0257 because it caused a
regression in SunSpider/string-fasta and possibly AreWeFastYet/Life.  Need to
implement this in a smarter way.

TBR=littledan@chromium.org
BUG=chromium:627729,v8:5113

Review-Url: https://codereview.chromium.org/2149303003
Cr-Commit-Position: refs/heads/master@{#37793}

src/js/array.js

@@ -151,7 +151,8 @@ function DoJoin(array, length, is_array, separator, convert) {
 
   // Fast case for one-element arrays.
   if (length === 1) {
-    return convert(array[0]);
+    var e = array[0];
+    return IS_STRING(e) ? e : convert(e);
   }
 
   // Construct an array for the elements.
@@ -160,14 +161,31 @@ function DoJoin(array, length, is_array, separator, convert) {
   // We pull the empty separator check outside the loop for speed!
   if (separator === '') {
     for (var i = 0; i < length; i++) {
-      elements[i] = convert(array[i]);
+      var e = array[i];
+      elements[i] = IS_STRING(e) ? e : convert(e);
     }
     return %StringBuilderConcat(elements, length, '');
   }
   // Non-empty separator case.
-  elements[0] = convert(array[0]);
-  for (var i = 1; i < length; i++) {
-    elements[i] = convert(array[i]);
+  // If the first element is a number then use the heuristic that the
+  // remaining elements are also likely to be numbers.
+  var e = array[0];
+  if (IS_NUMBER(e)) {
+    elements[0] = %_NumberToString(e);
+    for (var i = 1; i < length; i++) {
+      e = array[i];
+      if (IS_NUMBER(e)) {
+        elements[i] = %_NumberToString(e);
+      } else {
+        elements[i] = IS_STRING(e) ? e : convert(e);
+      }
+    }
+  } else {
+    elements[0] = IS_STRING(e) ? e : convert(e);
+    for (var i = 1; i < length; i++) {
+      e = array[i];
+      elements[i] = IS_STRING(e) ? e : convert(e);
+    }
   }
   return %StringBuilderJoin(elements, length, separator);
 }

test/mjsunit/array-tostring.js

@@ -125,9 +125,7 @@ var la1 = [1, [2, 3], 4];
 assertEquals("1,2,3,4", la1.toLocaleString());
 
 // Used on a string (which looks like an array of characters).
-String.prototype.toLocaleString = function() {
-  return (this.length == 1) ? this : Array.prototype.toLocaleString.call(this);
-}
+String.prototype.toLocaleString = Array.prototype.toLocaleString;
 assertEquals("1,2,3,4", "1234".toLocaleString());
 
 // If toLocaleString of element is not callable, throw a TypeError.
@@ -159,23 +157,3 @@ for (var i = 0; i < 3; i++) {
 }
 Number.prototype.arrayToLocaleString = Array.prototype.toLocaleString;
 assertEquals("42,42,42", (42).arrayToLocaleString());
-
-
-(function TestToLocaleStringCalls() {
-  let log = [];
-  let pushArgs = (label) => (...args) => log.push(label, args);
-
-  let NumberToLocaleString = Number.prototype.toLocaleString;
-  let StringToLocaleString = String.prototype.toLocaleString;
-  let ObjectToLocaleString = Object.prototype.toLocaleString;
-  Number.prototype.toLocaleString = pushArgs("Number");
-  String.prototype.toLocaleString = pushArgs("String");
-  Object.prototype.toLocaleString = pushArgs("Object");
-
-  [42, "foo", {}].toLocaleString();
-  assertEquals(["Number", [], "String", [], "Object", []], log);
-
-  Number.prototype.toLocaleString = NumberToLocaleString;
-  String.prototype.toLocaleString = StringToLocaleString;
-  Object.prototype.toLocaleString = ObjectToLocaleString;
-})();

test/mjsunit/es6/typedarray-tostring.js

@@ -83,17 +83,4 @@ for (var constructor of typedArrayConstructors) {
   assertEquals("1,2", Array.prototype.join.call(a5));
   assertEquals("1,2,3", Array.prototype.toString.call(a5));
   assertEquals("1,2", Array.prototype.toLocaleString.call(a5));
-
-  (function TestToLocaleStringCalls() {
-    let log = [];
-    let pushArgs = (label) => (...args) => log.push(label, args);
-
-    let NumberToLocaleString = Number.prototype.toLocaleString;
-    Number.prototype.toLocaleString = pushArgs("Number");
-
-    (new constructor([1, 2])).toLocaleString();
-    assertEquals(["Number", [], "Number", []], log);
-
-    Number.prototype.toLocaleString = NumberToLocaleString;
-  })();
 }

test/test262/test262.status

@@ -335,6 +335,17 @@
   # https://bugs.chromium.org/p/v8/issues/detail?id=5012
   'intl402/Intl/getCanonicalLocales/*': [FAIL],
 
+  # https://bugs.chromium.org/p/v8/issues/detail?id=5113
+  'built-ins/TypedArray/prototype/toLocaleString/calls-tolocalestring-from-each-value': [FAIL],
+  'built-ins/TypedArray/prototype/toLocaleString/calls-tostring-from-each-value': [FAIL],
+  'built-ins/TypedArray/prototype/toLocaleString/calls-valueof-from-each-value': [FAIL],
+  'built-ins/TypedArray/prototype/toLocaleString/return-abrupt-from-firstelement-tolocalestring': [FAIL],
+  'built-ins/TypedArray/prototype/toLocaleString/return-abrupt-from-firstelement-tostring': [FAIL],
+  'built-ins/TypedArray/prototype/toLocaleString/return-abrupt-from-firstelement-valueof': [FAIL],
+  'built-ins/TypedArray/prototype/toLocaleString/return-abrupt-from-nextelement-tolocalestring': [FAIL],
+  'built-ins/TypedArray/prototype/toLocaleString/return-abrupt-from-nextelement-tostring': [FAIL],
+  'built-ins/TypedArray/prototype/toLocaleString/return-abrupt-from-nextelement-valueof': [FAIL],
+
   # https://bugs.chromium.org/p/v8/issues/detail?id=5115
   'language/statements/class/subclass/class-definition-null-proto-missing-return-override': [FAIL],
   'language/statements/class/subclass/class-definition-null-proto-this': [FAIL],