move variable down to where it is used

Author: RalfJung

src/liballoc/collections/vec_deque.rs

@@ -3094,11 +3094,6 @@ mod tests {
     fn test_vec_from_vecdeque() {
         use crate::vec::Vec;
 
-        #[cfg(not(miri))] // Miri is too slow
-        let max_pwr = 7;
-        #[cfg(miri)]
-        let max_pwr = 5;
-
         fn create_vec_and_test_convert(cap: usize, offset: usize, len: usize) {
             let mut vd = VecDeque::with_capacity(cap);
             for _ in 0..offset {
@@ -3112,6 +3107,11 @@ mod tests {
             assert!(vec.into_iter().eq(vd));
         }
 
+        #[cfg(not(miri))] // Miri is too slow
+        let max_pwr = 7;
+        #[cfg(miri)]
+        let max_pwr = 5;
+
         for cap_pwr in 0..max_pwr {
             // Make capacity as a (2^x)-1, so that the ring size is 2^x
             let cap = (2i32.pow(cap_pwr) - 1) as usize;