[runtime] Port simple String.prototype.indexOf cases to TF Builtin

src/assembler.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 1011 matching lines @@
   static ExternalReference ieee754_expm1_function(Isolate* isolate);
   static ExternalReference ieee754_log_function(Isolate* isolate);
   static ExternalReference ieee754_log1p_function(Isolate* isolate);
   static ExternalReference ieee754_log10_function(Isolate* isolate);
   static ExternalReference ieee754_log2_function(Isolate* isolate);
   static ExternalReference ieee754_sin_function(Isolate* isolate);
   static ExternalReference ieee754_sinh_function(Isolate* isolate);
   static ExternalReference ieee754_tan_function(Isolate* isolate);
   static ExternalReference ieee754_tanh_function(Isolate* isolate);
 
+  static ExternalReference libc_memchr_function(Isolate* isolate);
+
   static ExternalReference page_flags(Page* page);
 
   static ExternalReference ForDeoptEntry(Address entry);
 
   static ExternalReference cpu_features();
 
   static ExternalReference is_tail_call_elimination_enabled_address(
       Isolate* isolate);
 
   static ExternalReference debug_is_active_address(Isolate* isolate);
@@ skipping 68 matching lines @@
 
 V8_EXPORT_PRIVATE bool operator==(ExternalReference, ExternalReference);
 bool operator!=(ExternalReference, ExternalReference);
 
 size_t hash_value(ExternalReference);
 
 V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream&, ExternalReference);
 
 // -----------------------------------------------------------------------------
 // Utility functions
+void* libc_memchr(void* string, int character, size_t search_length);
 
 inline int NumberOfBitsSet(uint32_t x) {
   unsigned int num_bits_set;
   for (num_bits_set = 0; x; x >>= 1) {
     num_bits_set += x & 1;
   }
   return num_bits_set;
 }
 
 // Computes pow(x, y) with the special cases in the spec for Math.pow.
@@ skipping 152 matching lines @@
     std::vector<ConstantPoolEntry> shared_entries;
   };
 
   Label emitted_label_;  // Records pc_offset of emitted pool
   PerTypeEntryInfo info_[ConstantPoolEntry::NUMBER_OF_TYPES];
 };
 
 }  // namespace internal
 }  // namespace v8
 #endif  // V8_ASSEMBLER_H_