Remove unused asm.rs

src/lib.rs

@@ -7,7 +7,6 @@
 // N.B. these crates are loaded from the sysroot, so they need extern crate.
 extern crate rustc_ast;
 extern crate rustc_ast_pretty;
-extern crate rustc_builtin_macros;
 extern crate rustc_data_structures;
 extern crate rustc_errors;
 extern crate rustc_expand;

src/parse/macros/mod.rs

@@ -9,7 +9,6 @@ use rustc_span::symbol;
 use crate::macros::MacroArg;
 use crate::rewrite::RewriteContext;
 
-pub(crate) mod asm;
 pub(crate) mod cfg_if;
 pub(crate) mod cfg_match;
 pub(crate) mod lazy_static;