Remove outdated errors for mutating strings

src/test/compile-fail/str-mut-idx-2.rs

@@ -0,0 +1,16 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn mutate(mut s: &mut str) {
+    let _s: &mut str = &mut s[1..2];
+    //~^ ERROR cannot borrow immutable indexed content as mutable
+}
+
+pub fn main() {}

src/test/compile-fail/str-mut-idx.rs

@@ -0,0 +1,22 @@
+// Copyright 2015 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn bot<T>() -> T { loop {} }
+
+fn mutate(s: &mut str) {
+    s[1..2] = bot();
+    //~^ ERROR `core::marker::Sized` is not implemented for the type `str`
+    //~^^ ERROR `core::marker::Sized` is not implemented for the type `str`
+    s[1usize] = bot();
+    //~^ ERROR `core::ops::Index<usize>` is not implemented for the type `str`
+    //~^^ ERROR `core::ops::Index<usize>` is not implemented for the type `str`
+}
+
+pub fn main() {}