Move #[allow(box_pointers)] to the narrowest scope it is needed.

`#[allow(box_pointers)]` is only needed in uninteresting code, so
move it to exactly where it is needed.

build.rs

@@ -14,7 +14,7 @@
 
 //! Build the non-Rust components.
 
-#![allow(
+#![deny(
     box_pointers,
 )]
 
@@ -291,6 +291,7 @@ fn ring_build_rs_main() {
             cfg = cfg.num_threads(amt);
         }
     }
+    #[allow(box_pointers)]
     rayon::initialize(cfg).unwrap();
 
     for (key, value) in env::vars() {
@@ -450,6 +451,7 @@ fn build_library(target: &Target, out_dir: &Path, lib_name: &str,
                  srcs: &[PathBuf], additional_srcs: &[PathBuf],
                  warnings_are_errors: bool, includes_modified: SystemTime) {
     // Compile all the (dirty) source files into object files.
+    #[allow(box_pointers)] // XXX
     let objs = additional_srcs.into_par_iter().chain(srcs.into_par_iter())
         .with_max_len(1)
         .filter(|f|

src/lib.rs

@@ -37,7 +37,6 @@
 #![doc(html_root_url="https://briansmith.org/rustdoc/")]
 
 #![allow(
-    box_pointers,
     legacy_directory_ownership,
     missing_copy_implementations,
     missing_debug_implementations,
@@ -46,6 +45,7 @@
 
 // `#[derive(...)]` uses `#[allow(unused_qualifications )]` internally.
 #![deny(
+    box_pointers,
     missing_docs,
     trivial_numeric_casts,
     unstable_features,

src/test.rs

@@ -251,6 +251,7 @@ pub fn from_file<F>(test_data_relative_file_path: &str, mut f: F)
     let mut current_section = String::from("");
     let mut failed = false;
 
+    #[allow(box_pointers)]
     while let Some(mut test_case) = parse_test_case(&mut current_section,
                                                     &mut lines) {
         let result =