review comments

src/librustc_resolve/lib.rs

@@ -2893,7 +2893,7 @@ fn names_to_string(names: &[Name]) -> String {
  if i > 0 {
  result.push_str("::");
  }
- if name.is_used_keyword() && name.can_be_raw() {
+ if Ident::with_dummy_span(*name).is_raw_guess() {
  result.push_str("r#");
  }
  result.push_str(&name.as_str());

src/libsyntax_pos/symbol.rs

@@ -1013,15 +1013,7 @@ pub mod sym {
 }
 
 impl Symbol {
- pub fn is_used_keyword(self) -> bool {
- self.is_used_keyword_2015() || self.is_used_keyword_2018()
- }
-
- pub fn is_used_keyword_2015(self) -> bool {
- self >= kw::As && self <= kw::While
- }
-
- pub fn is_used_keyword_2018(self) -> bool {
+ fn is_used_keyword_2018(self) -> bool {
  self >= kw::Async && self <= kw::Dyn
  }
 
@@ -1065,7 +1057,7 @@ impl Ident {
  /// Returns `true` if the token is a keyword used in the language.
  pub fn is_used_keyword(self) -> bool {
  // Note: `span.edition()` is relatively expensive, don't call it unless necessary.
- self.name.is_used_keyword_2015() ||
+ self.name >= kw::As && self.name <= kw::While ||
  self.name.is_used_keyword_2018() && self.span.rust_2018()
  }