[builtins] Migrate String.prototype.trim/trimLeft/trimRight to C++.

src/runtime/runtime-strings.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/regexp/jsregexp-inl.h"
 #include "src/string-builder.h"
 #include "src/string-search.h"
@@ skipping 1070 matching lines @@
 }
 
 
 RUNTIME_FUNCTION(Runtime_StringToUpperCase) {
   HandleScope scope(isolate);
   DCHECK_EQ(args.length(), 1);
   CONVERT_ARG_HANDLE_CHECKED(String, s, 0);
   return ConvertCase(s, isolate, isolate->runtime_state()->to_upper_mapping());
 }
 
-
-RUNTIME_FUNCTION(Runtime_StringTrim) {
-  HandleScope scope(isolate);
-  DCHECK(args.length() == 3);
-
-  CONVERT_ARG_HANDLE_CHECKED(String, string, 0);
-  CONVERT_BOOLEAN_ARG_CHECKED(trimLeft, 1);
-  CONVERT_BOOLEAN_ARG_CHECKED(trimRight, 2);
-
-  string = String::Flatten(string);
-  int length = string->length();
-
-  int left = 0;
-  UnicodeCache* unicode_cache = isolate->unicode_cache();
-  if (trimLeft) {
-    while (left < length &&
-           unicode_cache->IsWhiteSpaceOrLineTerminator(string->Get(left))) {
-      left++;
-    }
-  }
-
-  int right = length;
-  if (trimRight) {
-    while (
-        right > left &&
-        unicode_cache->IsWhiteSpaceOrLineTerminator(string->Get(right - 1))) {
-      right--;
-    }
-  }
-
-  return *isolate->factory()->NewSubString(string, left, right);
-}
-
 RUNTIME_FUNCTION(Runtime_StringLessThan) {
   HandleScope handle_scope(isolate);
   DCHECK_EQ(2, args.length());
   CONVERT_ARG_HANDLE_CHECKED(String, x, 0);
   CONVERT_ARG_HANDLE_CHECKED(String, y, 1);
   switch (String::Compare(x, y)) {
     case ComparisonResult::kLessThan:
       return isolate->heap()->true_value();
     case ComparisonResult::kEqual:
     case ComparisonResult::kGreaterThan:
@@ skipping 106 matching lines @@
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 2);
   if (!args[0]->IsString()) return isolate->heap()->undefined_value();
   if (!args[1]->IsNumber()) return isolate->heap()->undefined_value();
   if (std::isinf(args.number_at(1))) return isolate->heap()->nan_value();
   return __RT_impl_Runtime_StringCharCodeAtRT(args, isolate);
 }
 
 }  // namespace internal
 }  // namespace v8