Make nghttp2_is_fatal public API

lib/includes/nghttp2/nghttp2.h

@@ -2374,6 +2374,14 @@ int nghttp2_gzip_inflate(nghttp2_gzip *inflater,
  */
 nghttp2_info *nghttp2_version(int least_version);
 
+/**
+ * @function
+ *
+ * Returns nonzero if the :type:`nghttp2_error` library error code
+ * |lib_error| is fatal.
+ */
+int nghttp2_is_fatal(int lib_error);
+
 #ifdef __cplusplus
 }
 #endif

lib/nghttp2_session.c

@@ -64,12 +64,9 @@ static int nghttp2_is_non_fatal(int error)
   return error < 0 && error > NGHTTP2_ERR_FATAL;
 }
 
-/*
- * Returns non-zero if |error| is fatal error.
- */
-static int nghttp2_is_fatal(int error)
+int nghttp2_is_fatal(int lib_error)
 {
-  return error < NGHTTP2_ERR_FATAL;
+  return lib_error < NGHTTP2_ERR_FATAL;
 }
 
 /* Returns the pushed stream's priority based on the associated stream