Checkin new types for RS.

Change-Id: I3d7a1a91c45cc1c97c60f3615f32e54e98e12f91
diff --git a/scriptc/rs_graphics.rsh b/scriptc/rs_graphics.rsh
index 70cd562..0f03732 100644
--- a/scriptc/rs_graphics.rsh
+++ b/scriptc/rs_graphics.rsh
@@ -1,5 +1,7 @@
 
 
+extern float rand(float max);
+
 extern float2 vec2Rand(float len);
 
 extern float3 float3Norm(float3);