Reduce P<T> to a typedef of Box<T>.

Keep the `P` constructor function for now, to minimize immediate churn.

All the `into_inner` calls are removed, which is nice.

Author: nnethercote

src/modules.rs

@@ -174,7 +174,7 @@ impl<'ast, 'psess, 'c> ModResolver<'ast, 'psess> {
     ) -> Result<(), ModuleResolutionError> {
         for item in items {
             if is_cfg_if(&item) {
-                self.visit_cfg_if(Cow::Owned(item.into_inner()))?;
+                self.visit_cfg_if(Cow::Owned(*item))?;
                 continue;
             }
 

src/parse/macros/cfg_if.rs

@@ -62,7 +62,7 @@ fn parse_cfg_if_inner<'a>(
 
         while parser.token != TokenKind::CloseBrace && parser.token.kind != TokenKind::Eof {
             let item = match parser.parse_item(ForceCollect::No) {
-                Ok(Some(item_ptr)) => item_ptr.into_inner(),
+                Ok(Some(item_ptr)) => *item_ptr,
                 Ok(None) => continue,
                 Err(err) => {
                     err.cancel();