use crate::util::check_builtin_macro_attribute;
use rustc_expand::base::{Annotatable, ExtCtxt};
+use rustc_span::symbol::{kw, sym, Symbol};
use rustc_span::Span;
use syntax::ast::{self, Attribute, Expr, FnHeader, FnSig, Generics, Ident, Param};
use syntax::ast::{ItemKind, Mutability, Stmt, Ty, TyKind, Unsafety};
use syntax::expand::allocator::{AllocatorKind, AllocatorMethod, AllocatorTy, ALLOCATOR_METHODS};
use syntax::ptr::P;
-use syntax::symbol::{kw, sym, Symbol};
pub fn expand(
ecx: &mut ExtCtxt<'_>,