Fix nits

Author: GuillaumeGomez

src/bootstrap/test.rs

@@ -919,8 +919,6 @@ impl Step for Compiletest {
             if build.config.rust_debuginfo_tests {
                 flags.push("-g".to_string());
             }
-        }
-        if !is_rustdoc_ui {
             flags.push("-Zmiri -Zunstable-options".to_string());
         } else {
             flags.push("-Zunstable-options".to_string());

src/test/rustdoc-ui/intra-links-warning.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![deny(warnings)]
-
 // must-compile-successfully
 
 //! Test with [Foo::baz], [Bar::foo], [Uniooon::X]