Add sincosl() function to bionic. So that sincos optimization can
be enabled.

Change-Id: I19671a407dc96a92417c719da938ee0c1669bfb8
diff --git a/libm/sincos.c b/libm/sincos.c
index ddbc420..116b151 100644
--- a/libm/sincos.c
+++ b/libm/sincos.c
@@ -38,3 +38,9 @@
     *psin = sinf(x);
     *pcos = cosf(x);
 }
+
+void  sincosl(long double x, long double *psin, long double *pcos)
+{
+    *psin = sin(x);
+    *pcos = cos(x);
+}