Fix some warnings on nightly Rust (#3148)

Looks like these trailing-semicolons-in-macros are likely to become a
hard error in the future, so this updates to remove them as necessary.

cranelift/codegen/meta/src/srcgen.rs

@@ -19,19 +19,19 @@ static SHIFTWIDTH: usize = 4;
 /// strings.
 macro_rules! fmtln {
     ($fmt:ident, $fmtstring:expr, $($fmtargs:expr),*) => {
-        $fmt.line(format!($fmtstring, $($fmtargs),*));
+        $fmt.line(format!($fmtstring, $($fmtargs),*))
     };
 
     ($fmt:ident, $arg:expr) => {
-        $fmt.line($arg);
+        $fmt.line($arg)
     };
 
     ($_:tt, $($args:expr),+) => {
-        compile_error!("This macro requires at least two arguments: the Formatter instance and a format string.");
+        compile_error!("This macro requires at least two arguments: the Formatter instance and a format string.")
     };
 
     ($_:tt) => {
-        compile_error!("This macro requires at least two arguments: the Formatter instance and a format string.");
+        compile_error!("This macro requires at least two arguments: the Formatter instance and a format string.")
     };
 }
 

crates/cache/src/worker.rs

@@ -556,7 +556,7 @@ impl WorkerThread {
                     vec.push(CacheEntry::Unrecognized {
                         path: $path.to_path_buf(),
                         is_dir: $is_dir,
-                    });
+                    })
                 };
             }
             macro_rules! add_unrecognized_and {

crates/debug/src/transform/expression.rs

@@ -386,7 +386,7 @@ impl CompiledExpression {
                                     }
                                 } else {
                                     return Ok(None);
-                                };
+                                }
                             };
                         }
                         for part in &self.parts {