move asm parsing code into rustc_parse

Author: folkertdev

src/lib.rs

@@ -8,7 +8,6 @@
 // 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/asm.rs

@@ -1,5 +1,5 @@
 use rustc_ast::ast;
-use rustc_builtin_macros::asm::{AsmArg, parse_asm_args};
+use rustc_parse::parser::asm::{AsmArg, parse_asm_args};
 
 use crate::rewrite::RewriteContext;