Revert "Ship well-formed JSON.stringify 🎉"

This reverts commit 0d91db0b.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> Ship well-formed JSON.stringify 🎉
> 
> Proposal repository:
> https://github.com/tc39/proposal-global
> 
> Intent to ship:
> https://groups.google.com/d/msg/v8-users/IRu3bAC_pLM/pFwz2ti1AgAJ
> 
> Bug: v8:7782
> Change-Id: Iaf790f134917796deac0e84cc931828934a6e589
> Reviewed-on: https://chromium-review.googlesource.com/c/1260122
> Commit-Queue: Mathias Bynens <mathias@chromium.org>
> Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#56650}

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

Change-Id: Ie214a72a01fa81f754fd411808eb0bb748f89dbb
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:7782
Reviewed-on: https://chromium-review.googlesource.com/c/1282563Reviewed-by: Mathias Bynens <mathias@chromium.org>
Commit-Queue: Mathias Bynens <mathias@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56663}

src/flag-definitions.h

@@ -234,18 +234,18 @@ DEFINE_IMPLICATION(harmony_class_fields, harmony_private_fields)
   V(harmony_private_fields, "harmony private fields in class literals")    \
   V(harmony_numeric_separator, "harmony numeric separator between digits") \
   V(harmony_string_matchall, "harmony String.prototype.matchAll")          \
-  V(harmony_static_fields, "harmony static fields in class literals")
+  V(harmony_static_fields, "harmony static fields in class literals")      \
+  V(harmony_json_stringify, "Well-formed JSON.stringify")
 
 // Features that are shipping (turned on by default, but internal flag remains).
-#define HARMONY_SHIPPING_BASE(V)                                        \
-  V(harmony_sharedarraybuffer, "harmony sharedarraybuffer")             \
-  V(harmony_import_meta, "harmony import.meta property")                \
-  V(harmony_dynamic_import, "harmony dynamic import")                   \
-  V(harmony_array_prototype_values, "harmony Array.prototype.values")   \
-  V(harmony_array_flat, "harmony Array.prototype.{flat,flatMap}")       \
-  V(harmony_symbol_description, "harmony Symbol.prototype.description") \
-  V(harmony_global, "harmony global")                                   \
-  V(harmony_json_stringify, "well-formed JSON.stringify")
+#define HARMONY_SHIPPING_BASE(V)                                         \
+  V(harmony_sharedarraybuffer, "harmony sharedarraybuffer")              \
+  V(harmony_import_meta, "harmony import.meta property")                 \
+  V(harmony_dynamic_import, "harmony dynamic import")                    \
+  V(harmony_array_prototype_values, "harmony Array.prototype.values")    \
+  V(harmony_array_flat, "harmony Array.prototype.{flat,flatMap}")        \
+  V(harmony_symbol_description, "harmony Symbol.prototype.description")  \
+  V(harmony_global, "harmony global")
 
 #ifdef V8_INTL_SUPPORT
 #define HARMONY_SHIPPING(V) \

test/mjsunit/json.js

@@ -390,9 +390,11 @@ for (var i = 0x0000; i <= 0xFFFF; i++) {
     else if (string == '\n') expected = '\\n';
     else if (string == '\f') expected = '\\f';
     else if (string == '\r') expected = '\\r';
-  } else if (i < 0x20 || (i >= 0xD800 && i <= 0xDFFF)) {
+  } else if (i < 0x20) {
     // Step 2.c
     expected = '\\u' + i.toString(16).padStart(4, '0');
+    // TODO(mathias): Add i >= 0xD800 && i <= 0xDFFF case once
+    // --harmony-json-stringify is enabled by default.
   } else {
     expected = string;
   }

test/webkit/resources/JSON-stringify.js

@@ -82,19 +82,19 @@ function createTests() {
     });
     result.push(function (jsonObject){
         var value = new Number(1);
-        value.valueOf = function() { return 2; };
+        value.valueOf = function() { return 2; }
         return jsonObject.stringify(value);
     });
     result[result.length - 1].expected = '2';
     result.push(function (jsonObject){
         var value = new Boolean(true);
-        value.valueOf = function() { return 2; };
+        value.valueOf = function() { return 2; }
         return jsonObject.stringify(value);
     });
     result[result.length - 1].expected = '2';
     result.push(function (jsonObject){
         var value = new String("fail");
-        value.toString = function() { return "converted string"; };
+        value.toString = function() { return "converted string"; }
         return jsonObject.stringify(value);
     });
     result[result.length - 1].expected = '"converted string"';
@@ -429,7 +429,7 @@ function createTests() {
     result[result.length - 1].throws = true;
     result.push(function (jsonObject){
         cycleTracker = "";
-        try { jsonObject.stringify(cyclicArray); } catch { cycleTracker += " -> exception" }
+        try { jsonObject.stringify(cyclicArray); } catch(e) { cycleTracker += " -> exception" }
         return cycleTracker;
     });
     result[result.length - 1].expected = "0(number):[object Object]first, -> exception";
@@ -508,7 +508,7 @@ function createTests() {
         return jsonObject.stringify(toDeepVirtualJSONArray());
     });
     var fullCharsetString = "";
-    for (let i = 0; i <= 0xFFFF; i++)
+    for (var i = 0; i < 65536; i++)
         fullCharsetString += String.fromCharCode(i);
     result.push(function (jsonObject){
         return jsonObject.stringify(fullCharsetString);

test/webkit/resources/json2-es5-compat.js

@@ -186,7 +186,7 @@ if (!this.JSON) {
     }
 
     var cx = /[\u0000\u00ad\u0600-\u0604\u070f\u17b4\u17b5\u200c-\u200f\u2028-\u202f\u2060-\u206f\ufeff\ufff0-\uffff]/g,
-        escapable = /[\\\"\x00-\x1F]|[\uD800-\uDBFF](?![\uDC00-\uDFFF])|(?<![\uD800-\uDBFF])[\uDC00-\uDFFF]/g,
+        escapable = /[\\\"\x00-\x1f]/g,
         gap,
         indent,
         meta = {    // table of character substitutions
@@ -203,17 +203,17 @@ if (!this.JSON) {
 
     function quote(string) {
 
-// If the string contains no control characters, no quote characters, no
-// backslash characters, and no lone surrogates, then we can safely
-// slap some quotes around it. Otherwise we must also replace the
-// offending characters with safe escape sequences.
+// If the string contains no control characters, no quote characters, and no
+// backslash characters, then we can safely slap some quotes around it.
+// Otherwise we must also replace the offending characters with safe escape
+// sequences.
 
         escapable.lastIndex = 0;
         return escapable.test(string) ?
             '"' + string.replace(escapable, function (a) {
                 var c = meta[a];
                 return typeof c === 'string' ? c :
-                    '\\u' + a.charCodeAt(0).toString(16).padStart(4, '0');
+                    '\\u' + ('0000' + a.charCodeAt(0).toString(16)).slice(-4);
             }) + '"' :
             '"' + string + '"';
     }

test/webkit/run-json-stringify-expected.txt

@@ -52,19 +52,19 @@ function (jsonObject){
 PASS tests[i](nativeJSON) is tests[i](JSON)
 function (jsonObject){
         var value = new Number(1);
-        value.valueOf = function() { return 2; };
+        value.valueOf = function() { return 2; }
         return jsonObject.stringify(value);
     }
 PASS tests[i](nativeJSON) is tests[i].expected
 function (jsonObject){
         var value = new Boolean(true);
-        value.valueOf = function() { return 2; };
+        value.valueOf = function() { return 2; }
         return jsonObject.stringify(value);
     }
 FAIL tests[i](nativeJSON) should be 2. Was true.
 function (jsonObject){
         var value = new String("fail");
-        value.toString = function() { return "converted string"; };
+        value.toString = function() { return "converted string"; }
         return jsonObject.stringify(value);
     }
 PASS tests[i](nativeJSON) is tests[i].expected
@@ -448,7 +448,7 @@ function (jsonObject){
 PASS tests[i](nativeJSON) threw exception TypeError: Converting circular structure to JSON.
 function (jsonObject){
         cycleTracker = "";
-        try { jsonObject.stringify(cyclicArray); } catch { cycleTracker += " -> exception" }
+        try { jsonObject.stringify(cyclicArray); } catch(e) { cycleTracker += " -> exception" }
         return cycleTracker;
     }
 FAIL tests[i](nativeJSON) should be 0(number):[object Object]first, -> exception. Was 0(string):[object Object]first, -> exception.
@@ -541,3 +541,4 @@ PASS tests[i](nativeJSON) is tests[i](JSON)
 PASS successfullyParsed is true
 
 TEST COMPLETE
+