WIP: Signal handling

src/scheme/sys/context.rs

@@ -72,6 +72,9 @@ pub fn resource() -> Result<Vec<u8>> {
             if let Some(ref stack) = context.stack {
                 memory += stack.size();
             }
+            if let Some(ref sigstack) = context.sigstack {
+                memory += sigstack.size();
+            }
 
             let memory_string = if memory >= 1024 * 1024 * 1024 {
                 format!("{} GB", memory / 1024 / 1024 / 1024)