Revert "[Intl] remove unused js"

This reverts commit 2dc505a4.

Reason for revert: Breaks a layout test "fast/js/date-proto-generic-invocation.html" as can be seen in 
https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8-Blink%20Linux%2064/25626

Original change's description:
> [Intl] remove unused js
> 
> Bug: v8:8066
> Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
> Change-Id: I9d86577540cf227e038354d9661c60fcdc644b3f
> Reviewed-on: https://chromium-review.googlesource.com/1179467
> Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
> Commit-Queue: Frank Tang <ftang@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#55200}

TBR=gsathya@chromium.org,ftang@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: v8:8066
Change-Id: I4b6c7163a48f6f7fe439f8fd678abd053f60b020
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/1183163Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55251}

src/js/intl.js

@@ -26,6 +26,7 @@ var GlobalIntlNumberFormat = GlobalIntl.NumberFormat;
 var GlobalIntlCollator = GlobalIntl.Collator;
 var GlobalIntlPluralRules = GlobalIntl.PluralRules;
 var GlobalIntlv8BreakIterator = GlobalIntl.v8BreakIterator;
+var GlobalNumber = global.Number;
 var GlobalRegExp = global.RegExp;
 var GlobalString = global.String;
 var GlobalArray = global.Array;
@@ -38,6 +39,7 @@ var patternSymbol = utils.ImportNow("intl_pattern_symbol");
 var resolvedSymbol = utils.ImportNow("intl_resolved_symbol");
 var StringSubstr = GlobalString.prototype.substr;
 var StringSubstring = GlobalString.prototype.substring;
+var ArraySlice = GlobalArray.prototype.slice;
 
 utils.Import(function(from) {
   ArrayJoin = from.ArrayJoin;
@@ -46,10 +48,18 @@ utils.Import(function(from) {
 
 // Utilities for definitions
 
+macro IS_OBJECT(arg)
+(typeof(arg) === 'object')
+endmacro
+
 macro NUMBER_IS_NAN(arg)
 (%IS_VAR(arg) !== arg)
 endmacro
 
+macro NUMBER_IS_FINITE(arg)
+(%_IsSmi(%IS_VAR(arg)) || ((arg == arg) && (arg != 1/0) && (arg != -1/0)))
+endmacro
+
 // To avoid ES2015 Function name inference.
 
 macro ANONYMOUS_FUNCTION(fn)
@@ -514,6 +524,17 @@ function getAvailableLocalesOf(service) {
 }
 
 
+/**
+ * Adds property to an object if the value is not undefined.
+ * Sets configurable descriptor to false.
+ */
+function addWEPropertyIfDefined(object, property, value) {
+  if (!IS_UNDEFINED(value)) {
+    %DefineWEProperty(object, property, value);
+  }
+}
+
+
 /**
  * Defines a property and sets writable, enumerable and configurable to true.
  */