Upgrade to rustc 1.38.0-nightly (dddb7fca0 2019-07-30)

components/config/lib.rs

@@ -2,7 +2,6 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
-#![feature(core_intrinsics)]
 #![deny(unsafe_code)]
 
 #[macro_use]

components/config/pref_util.rs

@@ -116,7 +116,7 @@ macro_rules! impl_from_pref {
                         panic!(
                             format!("Cannot convert {:?} to {:?}",
                                 other,
-                                unsafe { std::intrinsics::type_name::<$t>() }
+                                std::any::type_name::<$t>()
                             )
                         );
                     }