Allow raw path-segment kw but not suggest escaping them

Author: mu001999

compiler/rustc_span/src/symbol.rs

@@ -3082,7 +3082,7 @@ impl Ident {
     /// We see this identifier in a normal identifier position, like variable name or a type.
     /// How was it written originally? Did it use the raw form? Let's try to guess.
     pub fn is_raw_guess(self) -> bool {
-        self.name.can_be_raw() && self.is_reserved()
+        self.name.can_be_raw() && !self.is_path_segment_keyword() && self.is_reserved()
     }
 
     /// Given the name of a lifetime without the first quote (`'`),

tests/ui/cfg/path-kw-as-pred.stderr

@@ -27,44 +27,24 @@ error: expected identifier, found keyword `crate`
    |
 LL | #[cfg_attr(crate, path = "foo")]
    |            ^^^^^ expected identifier, found keyword
-   |
-help: escape `crate` to use it as an identifier
-   |
-LL | #[cfg_attr(r#crate, path = "foo")]
-   |            ++
 
 error: expected identifier, found keyword `super`
   --> $DIR/path-kw-as-pred.rs:28:12
    |
 LL | #[cfg_attr(super, path = "foo")]
    |            ^^^^^ expected identifier, found keyword
-   |
-help: escape `super` to use it as an identifier
-   |
-LL | #[cfg_attr(r#super, path = "foo")]
-   |            ++
 
 error: expected identifier, found keyword `self`
   --> $DIR/path-kw-as-pred.rs:30:12
    |
 LL | #[cfg_attr(self, path = "foo")]
    |            ^^^^ expected identifier, found keyword
-   |
-help: escape `self` to use it as an identifier
-   |
-LL | #[cfg_attr(r#self, path = "foo")]
-   |            ++
 
 error: expected identifier, found keyword `Self`
   --> $DIR/path-kw-as-pred.rs:32:12
    |
 LL | #[cfg_attr(Self, path = "foo")]
    |            ^^^^ expected identifier, found keyword
-   |
-help: escape `Self` to use it as an identifier
-   |
-LL | #[cfg_attr(r#Self, path = "foo")]
-   |            ++
 
 error: expected identifier, found keyword `crate`
   --> $DIR/path-kw-as-pred.rs:34:22