Update compile fail test error messages

Author: fintelia

src/test/compile-fail/integral-indexing.rs

@@ -13,10 +13,10 @@ pub fn main() {
     let s: String = "abcdef".to_string();
     v[3_usize];
     v[3];
-    v[3u8];  //~ERROR : std::ops::Index<u8>` is not satisfied
-    v[3i8];  //~ERROR : std::ops::Index<i8>` is not satisfied
-    v[3u32]; //~ERROR : std::ops::Index<u32>` is not satisfied
-    v[3i32]; //~ERROR : std::ops::Index<i32>` is not satisfied
+    v[3u8];  //~ERROR : std::slice::SliceIndex<[isize]>` is not satisfied
+    v[3i8];  //~ERROR : std::slice::SliceIndex<[isize]>` is not satisfied
+    v[3u32]; //~ERROR : std::slice::SliceIndex<[isize]>` is not satisfied
+    v[3i32]; //~ERROR : std::slice::SliceIndex<[isize]>` is not satisfied
     s.as_bytes()[3_usize];
     s.as_bytes()[3];
     s.as_bytes()[3u8];  //~ERROR : std::slice::SliceIndex<[u8]>` is not satisfied