Make proc_macro::Group take up less space remove redundant field.

The field `entire` is redundant. This saves 4 bytes and makes the DelimSpan match up with what the compiler uses.

Author: Keith-Cancel

compiler/rustc_expand/src/proc_macro_server.rs

@@ -151,11 +151,7 @@ impl FromInternal<(TokenStream, &mut Rustc<'_, '_>)> for Vec<TokenTree<TokenStre
                     trees.push(TokenTree::Group(Group {
                         delimiter: rustc_proc_macro::Delimiter::from_internal(delim),
                         stream: Some(stream),
-                        span: DelimSpan {
-                            open: span.open,
-                            close: span.close,
-                            entire: span.entire(),
-                        },
+                        span: DelimSpan { open: span.open, close: span.close },
                     }));
                     continue;
                 }

library/proc_macro/src/bridge/mod.rs

@@ -420,16 +420,15 @@ compound_traits!(
 pub struct DelimSpan<Span> {
     pub open: Span,
     pub close: Span,
-    pub entire: Span,
 }
 
 impl<Span: Copy> DelimSpan<Span> {
     pub fn from_single(span: Span) -> Self {
-        DelimSpan { open: span, close: span, entire: span }
+        DelimSpan { open: span, close: span }
     }
 }
 
-compound_traits!(struct DelimSpan<Span> { open, close, entire });
+compound_traits!(struct DelimSpan<Span> { open, close });
 
 #[derive(Clone)]
 pub struct Group<TokenStream, Span> {

library/proc_macro/src/lib.rs

@@ -847,7 +847,8 @@ impl Group {
     /// ```
     #[stable(feature = "proc_macro_lib2", since = "1.29.0")]
     pub fn span(&self) -> Span {
-        Span(self.0.span.entire)
+        let sp = self.0.span;
+        Span(sp.open.join(sp.close).unwrap_or(sp.open))
     }
 
     /// Returns the span pointing to the opening delimiter of this group.