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

test/cctest/cctest.h

Index: test/cctest/cctest.h
diff --git a/test/cctest/cctest.h b/test/cctest/cctest.h
index 690a8c14cd40cf9b5b9d16117b183300280dce94..7d8ad59a269c61055597c6b9957324649a00a4b7 100644
--- a/test/cctest/cctest.h
+++ b/test/cctest/cctest.h
@@ -583,7 +583,6 @@ class InitializedHandleScope {
   std::unique_ptr<InitializedHandleScopeImpl> initialized_handle_scope_impl_;
 };
 
-
 class HandleAndZoneScope : public InitializedHandleScope {
  public:
   HandleAndZoneScope();
@@ -597,4 +596,18 @@ class HandleAndZoneScope : public InitializedHandleScope {
   std::unique_ptr<i::Zone> main_zone_;
 };
 
+class StaticOneByteResource : public v8::String::ExternalOneByteStringResource {
+ public:
+  explicit StaticOneByteResource(const char* data) : data_(data) {}
+
+  ~StaticOneByteResource() {}
+
+  const char* data() const { return data_; }
+
+  size_t length() const { return strlen(data_); }
+
+ private:
+  const char* data_;
+};
+
 #endif  // ifndef CCTEST_H_