[string] Widen StringIndexOf fast path

src/string-search.h

 // Copyright 2011 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.
 
 #ifndef V8_STRING_SEARCH_H_
 #define V8_STRING_SEARCH_H_
 
 #include "src/isolate.h"
 #include "src/vector.h"
 
@@ skipping 545 matching lines @@
 // for each search.
 template <typename SubjectChar, typename PatternChar>
 int SearchString(Isolate* isolate,
                  Vector<const SubjectChar> subject,
                  Vector<const PatternChar> pattern,
                  int start_index) {
   StringSearch<PatternChar, SubjectChar> search(isolate, pattern);
   return search.Search(subject, start_index);
 }
 
+// A wrapper function around SearchString that wraps raw pointers to the subject
+// and pattern as vectors before calling SearchString. Used from the
+// StringIndexOf builtin.
+template <typename SubjectChar, typename PatternChar>
+int SearchStringRaw(Isolate* isolate, const SubjectChar* subject_ptr,
+                    int subject_length, const PatternChar* pattern_ptr,
+                    int pattern_length, int start_index) {
+  DisallowHeapAllocation no_gc;
+  Vector<const SubjectChar> subject(subject_ptr, subject_length);
+  Vector<const PatternChar> pattern(pattern_ptr, pattern_length);
+  return SearchString(isolate, subject, pattern, start_index);
+}
+
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_STRING_SEARCH_H_