Automated sync from github.com/tensorflow/tensorflow (#2632)

BUG=automated sync from upstream
NO_CHECK_TFLITE_FILES=automated sync from upstream

tensorflow/lite/portable_type_to_tflitetype.h

diff --git a/tensorflow/lite/portable_type_to_tflitetype.h b/tensorflow/lite/portable_type_to_tflitetype.h
index b600585..03357db 100644
--- a/tensorflow/lite/portable_type_to_tflitetype.h
+++ b/tensorflow/lite/portable_type_to_tflitetype.h
@@ -52,6 +52,10 @@
     return TFLITE_TYPE_ENUM;                                   \
   }                                                            \
   template <>                                                  \
+  constexpr TfLiteType typeToTfLiteType<const CPP_TYPE>() {    \
+    return TFLITE_TYPE_ENUM;                                   \
+  }                                                            \
+  template <>                                                  \
   struct TfLiteTypeToType<TFLITE_TYPE_ENUM> {                  \
     using Type = CPP_TYPE;                                     \
   }