oss-fuzz: Add fuzzing targets for simplified READ API

New target added to libpng_read_fuzzer.cc for simplified READ API.
diff --git a/contrib/oss-fuzz/libpng_read_fuzzer.cc b/contrib/oss-fuzz/libpng_read_fuzzer.cc
index 0190cf7..ad9f9ad 100644
--- a/contrib/oss-fuzz/libpng_read_fuzzer.cc
+++ b/contrib/oss-fuzz/libpng_read_fuzzer.cc
@@ -204,5 +204,21 @@
   png_read_end(png_handler.png_ptr, png_handler.end_info_ptr);
 
   PNG_CLEANUP
+
+#ifdef PNG_SIMPLIFIED_READ_SUPPORTED
+  // Simplified READ API
+  png_image image;
+  memset(&image, 0, (sizeof image));
+  image.version = PNG_IMAGE_VERSION;
+
+  if (!png_image_begin_read_from_memory(&image, data, size)) {
+    return 0;
+  }
+
+  image.format = PNG_FORMAT_RGBA;
+  std::vector<png_byte> buffer(PNG_IMAGE_SIZE(image));
+  png_image_finish_read(&image, NULL, buffer.data(), 0, NULL);
+#endif
+
   return 0;
 }