Add unit test for Ed's fix

basis/locals/locals-tests.factor

@@ -346,7 +346,6 @@ M:: sequence method-with-locals ( a -- y ) a reverse ;
 
 { 3 1 } [| from to seq | T{ slice f from to seq } ] must-infer-as
 
-
 :: literal-identity-test ( -- a b )
     { } V{ } ;
 
@@ -356,6 +355,10 @@ M:: sequence method-with-locals ( a -- y ) a reverse ;
     swapd [ eq? ] [ eq? ] 2bi*
 ] unit-test
 
+:: mutable-local-in-literal-test ( a! -- b ) a 1 + a! { a } ;
+
+[ { 4 } ] [ 3 mutable-local-in-literal-test ] unit-test
+
 :: compare-case ( obj1 obj2 lt-quot eq-quot gt-quot -- )
     obj1 obj2 <=> {
         { +lt+ [ lt-quot call ] }