solitaire: Implement Keyed for Mut<T: Keyed>

Change-Id: I6680315db9ac2fe913a85b01b471572047cbe658

solana/solitaire/program/src/processors/keyed.rs

@@ -9,6 +9,7 @@ use crate::{
     Data,
     Derive,
     Info,
+    Mut,
     Signer,
     System,
     Sysvar,
@@ -59,6 +60,15 @@ where
     }
 }
 
+impl<'a, 'b: 'a, T> Keyed<'a, 'b> for Mut<T>
+where
+    T: Keyed<'a, 'b>,
+{
+    fn info(&'a self) -> &'a Info<'b> {
+        self.0.info()
+    }
+}
+
 impl<'a, 'b: 'a> Keyed<'a, 'b> for Info<'b> {
     fn info(&'a self) -> &'a Info<'b> {
         self