msvcrt: Add _atoldbl.
diff --git a/configure.ac b/configure.ac
index f44e3eb..efbf32d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1228,6 +1228,7 @@
 	strcasecmp \
 	strerror \
 	strncasecmp \
+	strtold \
 	tcgetattr \
 	timegm \
 	usleep \