fix(vm): Fix warning about upcoming breaking change

`as` needs to have the types specified so fix that

vm/src/thread.rs

@@ -198,7 +198,6 @@ impl<'vm> Deref for RootStr<'vm> {
     }
 }
 
-
 struct Roots<'b> {
     vm: GcPtr<Thread>,
     stack: &'b Stack,
@@ -557,9 +556,7 @@ impl Thread {
         // Finally check that type of the returned value is correct
         let expected = T::make_type(self);
         if check_signature(&*env, &expected, &actual) {
-            unsafe {
-                Ok(T::from_value(self, Variants::new(&value)))
-            }
+            unsafe { Ok(T::from_value(self, Variants::new(&value))) }
         } else {
             Err(Error::WrongType(expected, actual.into_owned()))
         }
@@ -650,10 +647,14 @@ impl Thread {
     {
         // For this to be safe we require that the received stack is the same one that is in this
         // VM
-        assert!(unsafe {
-            context as *const _ as usize >= &self.context as *const _ as usize
-                && context as *const _ as usize <= (&self.context as *const _).offset(1) as usize
-        });
+        {
+            let self_context: *const _ = &self.context;
+            let context: *const _ = context;
+            assert!(unsafe {
+                context as usize >= self_context as usize
+                    && context as usize <= self_context.offset(1) as usize
+            });
+        }
         let roots = Roots {
             vm: unsafe {
                 // Threads must only be on the garbage collectors heap which makes this safe
@@ -690,7 +691,6 @@ impl<'a> VmRoot<'a> for RootedThread {
     }
 }
 
-
 /// Internal functions for interacting with threads. These functions should be considered both
 /// unsafe and unstable.
 pub trait ThreadInternal
@@ -711,7 +711,6 @@ where
     where
         T: VmRoot<'vm>;
 
-
     /// Evaluates a zero argument function (a thunk)
     fn call_thunk(&self, closure: GcPtr<ClosureData>) -> FutureValue<Execute<&Self>>;
 
@@ -1949,7 +1948,6 @@ where
     binop(vm, stack, |l, r| Value::Tag(if f(l, r) { 1 } else { 0 }))
 }
 
-
 #[inline]
 fn binop<'b, F, T>(vm: &'b Thread, stack: &mut StackFrame<'b>, f: F)
 where