Revert of [regexp] Port RegExpCompile and RegExpToString (patchset #3 id:40001...

Revert of [regexp] Port RegExpCompile and RegExpToString (patchset #3 id:40001 of https://codereview.chromium.org/2295273003/ )

Reason for revert:
Performance regressions: crbug.com/644087
Clusterfuzz: crbug.com/644074

We'll reland all regexp changes at once when the port is complete and at least performance-neutral, since the partial port requires slow workarounds.

Original issue's description:
> [regexp] Port RegExpCompile and RegExpToString
>
> BUG=v8:5339
>
> Committed: https://crrev.com/836299aa9c484eb96b6b4aa48270ab2c30b85801
> Cr-Commit-Position: refs/heads/master@{#39119}

TBR=bmeurer@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=v8:5339

Review-Url: https://codereview.chromium.org/2311883002
Cr-Commit-Position: refs/heads/master@{#39170}

src/bootstrapper.cc

@@ -1636,12 +1636,6 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
                           Builtins::kRegExpPrototypeStickyGetter, false);
       SimpleInstallGetter(proto, factory->unicode_string(),
                           Builtins::kRegExpPrototypeUnicodeGetter, false);
-
-      SimpleInstallFunction(proto, "compile", Builtins::kRegExpPrototypeCompile,
-                            2, false, DONT_ENUM);
-      SimpleInstallFunction(proto, factory->toString_string(),
-                            Builtins::kRegExpPrototypeToString, 0, false,
-                            DONT_ENUM);
     }
 
     {

src/builtins/builtins-regexp.cc

@@ -148,36 +148,6 @@ BUILTIN(RegExpConstructor) {
                            RegExpInitialize(isolate, regexp, pattern, flags));
 }
 
-BUILTIN(RegExpPrototypeCompile) {
-  HandleScope scope(isolate);
-  CHECK_RECEIVER(JSRegExp, regexp, "RegExp.prototype.compile");
-
-  Handle<Object> pattern = args.atOrUndefined(isolate, 1);
-  Handle<Object> flags = args.atOrUndefined(isolate, 2);
-
-  if (pattern->IsJSRegExp()) {
-    Handle<JSRegExp> pattern_regexp = Handle<JSRegExp>::cast(pattern);
-
-    if (!flags->IsUndefined(isolate)) {
-      THROW_NEW_ERROR_RETURN_FAILURE(
-          isolate, NewTypeError(MessageTemplate::kRegExpFlags));
-    }
-
-    flags = PatternFlags(isolate, pattern_regexp);
-    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-        isolate, pattern,
-        Object::GetProperty(pattern, isolate->factory()->source_string()));
-  }
-
-  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-      isolate, regexp, RegExpInitialize(isolate, regexp, pattern, flags));
-
-  // Return undefined for compatibility with JSC.
-  // See http://crbug.com/585775 for web compat details.
-
-  return isolate->heap()->undefined_value();
-}
-
 #define APPEND_CHAR_FOR_FLAG(flag, c)                                        \
   do {                                                                       \
     Handle<Object> property;                                                 \
@@ -229,43 +199,6 @@ BUILTIN(RegExpPrototypeSourceGetter) {
   return regexp->source();
 }
 
-BUILTIN(RegExpPrototypeToString) {
-  HandleScope scope(isolate);
-  CHECK_RECEIVER(JSReceiver, recv, "RegExp.prototype.toString");
-
-  if (*recv == isolate->regexp_function()->prototype()) {
-    isolate->CountUsage(v8::Isolate::kRegExpPrototypeToString);
-  }
-
-  IncrementalStringBuilder builder(isolate);
-
-  builder.AppendCharacter('/');
-  {
-    Handle<Object> source;
-    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-        isolate, source,
-        JSReceiver::GetProperty(recv, isolate->factory()->source_string()));
-    Handle<String> source_str;
-    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, source_str,
-                                       Object::ToString(isolate, source));
-    builder.AppendString(source_str);
-  }
-
-  builder.AppendCharacter('/');
-  {
-    Handle<Object> flags;
-    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
-        isolate, flags,
-        JSReceiver::GetProperty(recv, isolate->factory()->flags_string()));
-    Handle<String> flags_str;
-    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, flags_str,
-                                       Object::ToString(isolate, flags));
-    builder.AppendString(flags_str);
-  }
-
-  RETURN_RESULT_OR_FAILURE(isolate, builder.Finish());
-}
-
 // ES6 21.2.4.2.
 BUILTIN(RegExpPrototypeSpeciesGetter) {
   HandleScope scope(isolate);

src/builtins/builtins.h

@@ -508,8 +508,6 @@ namespace internal {
                                                                               \
   /* RegExp */                                                                \
   CPP(RegExpConstructor)                                                      \
-  CPP(RegExpPrototypeCompile)                                                 \
-  CPP(RegExpPrototypeToString)                                                \
   CPP(RegExpPrototypeCapture1Getter)                                          \
   CPP(RegExpPrototypeCapture2Getter)                                          \
   CPP(RegExpPrototypeCapture3Getter)                                          \

src/js/regexp.js

@@ -71,6 +71,36 @@ function RegExpInitialize(object, pattern, flags) {
 }
 
 
+function PatternFlags(pattern) {
+  return (REGEXP_GLOBAL(pattern) ? 'g' : '') +
+         (REGEXP_IGNORE_CASE(pattern) ? 'i' : '') +
+         (REGEXP_MULTILINE(pattern) ? 'm' : '') +
+         (REGEXP_UNICODE(pattern) ? 'u' : '') +
+         (REGEXP_STICKY(pattern) ? 'y' : '');
+}
+
+
+// ES#sec-regexp.prototype.compile RegExp.prototype.compile (pattern, flags)
+function RegExpCompileJS(pattern, flags) {
+  if (!IS_REGEXP(this)) {
+    throw %make_type_error(kIncompatibleMethodReceiver,
+                        "RegExp.prototype.compile", this);
+  }
+
+  if (IS_REGEXP(pattern)) {
+    if (!IS_UNDEFINED(flags)) throw %make_type_error(kRegExpFlags);
+
+    flags = PatternFlags(pattern);
+    pattern = REGEXP_SOURCE(pattern);
+  }
+
+  RegExpInitialize(this, pattern, flags);
+
+  // Return undefined for compatibility with JSC.
+  // See http://crbug.com/585775 for web compat details.
+}
+
+
 function DoRegExpExec(regexp, string, index) {
   return %_RegExpExec(regexp, string, index, RegExpLastMatchInfo);
 }
@@ -305,6 +335,18 @@ function TrimRegExp(regexp) {
 }
 
 
+function RegExpToString() {
+  if (!IS_RECEIVER(this)) {
+    throw %make_type_error(
+        kIncompatibleMethodReceiver, 'RegExp.prototype.toString', this);
+  }
+  if (this === GlobalRegExp.prototype) {
+    %IncrementUseCounter(kRegExpPrototypeToString);
+  }
+  return '/' + TO_STRING(this.source) + '/' + TO_STRING(this.flags);
+}
+
+
 function AtSurrogatePair(subject, index) {
   if (index + 1 >= subject.length) return false;
   var first = %_StringCharCodeAt(subject, index);
@@ -887,6 +929,8 @@ function RegExpSubclassSearch(string) {
 utils.InstallFunctions(GlobalRegExp.prototype, DONT_ENUM, [
   "exec", RegExpSubclassExecJS,
   "test", RegExpSubclassTest,
+  "toString", RegExpToString,
+  "compile", RegExpCompileJS,
   matchSymbol, RegExpSubclassMatch,
   replaceSymbol, RegExpSubclassReplace,
   searchSymbol, RegExpSubclassSearch,