Add missing nanl

* Makefile.in (MATH_OFILES): Add nanl.o.
	* common.din (nanl): Export.
	* math/nanl.c: New file.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

winsup/cygwin/Makefile.in

@@ -220,6 +220,7 @@ MATH_OFILES:= \
 	lrintl.o \
 	lroundl.o \
 	modfl.o \
+	nanl.o \
 	nearbyint.o \
 	nearbyintf.o \
 	nearbyintl.o \

winsup/cygwin/common.din

@@ -894,6 +894,7 @@ munlock SIGFE
 munmap SIGFE
 nan NOSIGFE
 nanf NOSIGFE
+nanl NOSIGFE
 nanosleep SIGFE
 nearbyint NOSIGFE
 nearbyintf NOSIGFE

winsup/cygwin/math/nanl.c

@@ -0,0 +1,5 @@
+long double
+nanl (const char *tagp)
+{
+  return __builtin_nanl ("");
+}