rt: Cut the red zone to 10K on mac

Author: brson

src/rt/rust_task.cpp

@@ -18,8 +18,8 @@
 // FIXME: We want this to be 128 but need to slim the red zone calls down
 #define RZ_LINUX_32 (1024*2)
 #define RZ_LINUX_64 (1024*2)
-#define RZ_MAC_32   (1024*20)
-#define RZ_MAC_64   (1024*20)
+#define RZ_MAC_32   (1024*10)
+#define RZ_MAC_64   (1024*10)
 #define RZ_WIN_32   (1024*20)
 #define RZ_BSD_32   (1024*20)
 #define RZ_BSD_64   (1024*20)