Update to FreeBSD libm r336523.

This includes an ld128 powl, plus the clog* and cpow* families.

Also teach the NOTICE generator to strip SPDX-License-Identifier lines.

Bug: N/A
Test: ran tests
Change-Id: Ic8289d1253666a19468a4088884cf7540f1ec66d
diff --git a/libm/upstream-freebsd/lib/msun/src/s_csinh.c b/libm/upstream-freebsd/lib/msun/src/s_csinh.c
index 5f8380e..7408b13 100644
--- a/libm/upstream-freebsd/lib/msun/src/s_csinh.c
+++ b/libm/upstream-freebsd/lib/msun/src/s_csinh.c
@@ -39,7 +39,7 @@
  */
 
 #include <sys/cdefs.h>
-__FBSDID("$FreeBSD: head/lib/msun/src/s_csinh.c 326219 2017-11-26 02:00:33Z pfg $");
+__FBSDID("$FreeBSD: head/lib/msun/src/s_csinh.c 336362 2018-07-17 07:42:14Z bde $");
 
 #include <complex.h>
 #include <math.h>
@@ -145,7 +145,8 @@
 	 * Optionally raises the invalid floating-point exception for finite
 	 * nonzero y.  Choice = don't raise (except for signaling NaNs).
 	 */
-	return (CMPLX((x + x) * (y - y), (x * x) * (y - y)));
+	return (CMPLX(((long double)x + x) * (y - y),
+	    ((long double)x * x) * (y - y)));
 }
 
 double complex