So, I may have missed the update for config.h.in.   I am not sure this gets autogenerated or not.

--- config.h.in.orig 2017-02-18 13:27:19.000000000 -0800

+++ config.h.in 2017-02-18 13:27:45.000000000 -0800

@@ -2183,6 +2183,9 @@

 /* Define to 1 if you have the `sincos' function. */

 #undef HAVE_SINCOS

 

+/* Define to 1 if you have the `__sincos' function. */

+#undef HAVE___SINCOS

+

 /* Define to 1 if you have the `snprintf' function. */

 #undef HAVE_SNPRINTF