Enable and fix several more clippy lints.

lib/filetests/src/lib.rs

@@ -3,10 +3,20 @@
 //! This crate contains the main test driver as well as implementations of the
 //! available filetest commands.
 
+#![deny(missing_docs, trivial_numeric_casts, unused_extern_crates)]
+#![warn(unused_import_braces, unstable_features)]
 #![cfg_attr(feature="cargo-clippy", allow(
         type_complexity,
 // Rustfmt 0.9.0 is at odds with this lint:
         block_in_if_condition_stmt))]
+#![cfg_attr(feature="cargo-clippy", warn(
+                mut_mut,
+                nonminimal_bool,
+                option_map_unwrap_or,
+                option_map_unwrap_or_else,
+                unicode_not_nfc,
+                use_self,
+                ))]
 
 #[macro_use(dbg)]
 extern crate cretonne_codegen;

lib/filetests/src/runone.rs

@@ -122,7 +122,7 @@ fn run_one_test<'a>(
 ) -> Result<()> {
     let (test, flags, isa) = tuple;
     let name = format!("{}({})", test.name(), func.name);
-    dbg!("Test: {} {}", name, isa.map(TargetIsa::name).unwrap_or("-"));
+    dbg!("Test: {} {}", name, isa.map_or("-", TargetIsa::name));
 
     context.flags = flags;
     context.isa = isa;

lib/filetests/src/test_domtree.rs

@@ -125,7 +125,7 @@ fn filecheck_text(func: &Function, domtree: &DominatorTree) -> result::Result<St
     for &ebb in domtree.cfg_postorder() {
         write!(s, " {}", ebb)?;
     }
-    writeln!(s, "")?;
+    writeln!(s)?;
 
     // Compute and print out a pre-order of the dominator tree.
     writeln!(s, "domtree_preorder {{")?;
@@ -140,7 +140,7 @@ fn filecheck_text(func: &Function, domtree: &DominatorTree) -> result::Result<St
             write!(s, " {}", ch)?;
             stack.push(ch);
         }
-        writeln!(s, "")?;
+        writeln!(s)?;
         // Reverse the children we just pushed so we'll pop them in order.
         stack[i..].reverse();
     }