Revert of [regexp] Named capture support for string replacements

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 7b9923d1bcd29cd5a1cfdd68901fd6e0d763260e..d4185029dec568d67468947cd1e90ffd5bc3a297 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -11403,8 +11403,6 @@
 
 MaybeHandle<String> String::GetSubstitution(Isolate* isolate, Match* match,
                                             Handle<String> replacement) {
-  DCHECK_IMPLIES(match->HasNamedCaptures(), FLAG_harmony_regexp_named_captures);
-
   Factory* factory = isolate->factory();
 
   const int replacement_length = replacement->length();
@@ -11491,37 +11489,6 @@
         continue_from_ix = peek_ix + advance;
         break;
       }
-      case '<': {  // $<name> - named capture
-        if (!match->HasNamedCaptures()) {
-          builder.AppendCharacter('$');
-          continue_from_ix = peek_ix;
-          break;
-        }
-
-        Handle<String> bracket_string =
-            factory->LookupSingleCharacterStringFromCode('>');
-        const int closing_bracket_ix =
-            String::IndexOf(isolate, replacement, bracket_string, peek_ix + 1);
-
-        if (closing_bracket_ix == -1) {
-          THROW_NEW_ERROR(
-              isolate,
-              NewSyntaxError(MessageTemplate::kRegExpInvalidReplaceString,
-                             replacement),
-              String);
-        }
-
-        Handle<String> capture_name =
-            factory->NewSubString(replacement, peek_ix + 1, closing_bracket_ix);
-        bool capture_exists;
-        Handle<String> capture;
-        ASSIGN_RETURN_ON_EXCEPTION(
-            isolate, capture,
-            match->GetNamedCapture(capture_name, &capture_exists), String);
-        if (capture_exists) builder.AppendString(capture);
-        continue_from_ix = closing_bracket_ix + 1;
-        break;
-      }
       default:
         builder.AppendCharacter('$');
         continue_from_ix = peek_ix;
@@ -11692,15 +11659,6 @@
   return (allow_prefix_match || i == slen) && remaining_in_str == 0;
 }
 
-template <>
-bool String::IsEqualTo(Vector<const uint8_t> str) {
-  return IsOneByteEqualTo(str);
-}
-
-template <>
-bool String::IsEqualTo(Vector<const uc16> str) {
-  return IsTwoByteEqualTo(str);
-}
 
 bool String::IsOneByteEqualTo(Vector<const uint8_t> str) {
   int slen = length();