Attach TokenStream to ast::Block

A `Block` does not have outer attributes, so we only capture tokens when
parsing a `macro_rules!` matcher

compiler/rustc_parse/src/lib.rs

@@ -268,6 +268,7 @@ pub fn nt_to_tokenstream(nt: &Nonterminal, sess: &ParseSess, span: Span) -> Toke
         Nonterminal::NtItem(ref item) => {
             prepend_attrs(sess, &item.attrs, item.tokens.as_ref(), span)
         }
+        Nonterminal::NtBlock(ref block) => block.tokens.clone(),
         Nonterminal::NtPat(ref pat) => pat.tokens.clone(),
         Nonterminal::NtIdent(ident, is_raw) => {
             Some(tokenstream::TokenTree::token(token::Ident(ident.name, is_raw), ident.span).into())

compiler/rustc_parse/src/parser/nonterminal.rs

@@ -111,7 +111,14 @@ impl<'a> Parser<'a> {
                     return Err(self.struct_span_err(self.token.span, "expected an item keyword"));
                 }
             },
-            NonterminalKind::Block => token::NtBlock(self.parse_block()?),
+            NonterminalKind::Block => {
+                let (mut block, tokens) = self.collect_tokens(|this| this.parse_block())?;
+                // We have have eaten an NtBlock, which could already have tokens
+                if block.tokens.is_none() {
+                    block.tokens = Some(tokens);
+                }
+                token::NtBlock(block)
+            }
             NonterminalKind::Stmt => match self.parse_stmt()? {
                 Some(s) => token::NtStmt(s),
                 None => return Err(self.struct_span_err(self.token.span, "expected a statement")),

compiler/rustc_parse/src/parser/stmt.rs

@@ -411,7 +411,7 @@ impl<'a> Parser<'a> {
     }
 
     pub(super) fn mk_block(&self, stmts: Vec<Stmt>, rules: BlockCheckMode, span: Span) -> P<Block> {
-        P(Block { stmts, id: DUMMY_NODE_ID, rules, span })
+        P(Block { stmts, id: DUMMY_NODE_ID, rules, span, tokens: None })
     }
 
     pub(super) fn mk_stmt(&self, span: Span, kind: StmtKind) -> Stmt {