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

src/external-reference-table.cc

Index: src/external-reference-table.cc
diff --git a/src/external-reference-table.cc b/src/external-reference-table.cc
index 4c80116feb1b93de2226872e8c179c5b6ebd22e9..c645cfddd1acb75bfa050c01f89c0de81bfb67d2 100644
--- a/src/external-reference-table.cc
+++ b/src/external-reference-table.cc
@@ -230,6 +230,8 @@ void ExternalReferenceTable::AddReferences(Isolate* isolate) {
       "f64_mod_wrapper");
   Add(ExternalReference::wasm_call_trap_callback_for_testing(isolate).address(),
       "wasm::call_trap_callback_for_testing");
+  Add(ExternalReference::libc_memchr_function(isolate).address(),
+      "libc_memchr");
   Add(ExternalReference::log_enter_external_function(isolate).address(),
       "Logger::EnterExternal");
   Add(ExternalReference::log_leave_external_function(isolate).address(),