Auto merge of #46732 - estebank:silence-recovered-blocks, r=petrochenkov

Do not emit type errors on recovered blocks

When a parse error occurs on a block, the parser will recover and create
a block with the statements collected until that point. Now a flag
stating that a recovery has been performed in this block is propagated
so that the type checker knows that the type of the block (which will be
identified as `()`) shouldn't be checked against the expectation to
reduce the amount of irrelevant diagnostic errors shown to the user.

Fix #44579.

src/libsyntax/parse/mod.rs

@@ -930,6 +930,7 @@ fn parser_done(p: Parser){
                                         id: ast::DUMMY_NODE_ID,
                                         rules: ast::BlockCheckMode::Default, // no idea
                                         span: sp(15,21),
+                                        recovered: false,
                                     })),
                             vis: ast::Visibility::Inherited,
                             span: sp(0,21)})));

src/libsyntax/parse/parser.rs

@@ -4372,13 +4372,15 @@ fn parse_inner_attrs_and_block(&mut self) -> PResult<'a, (Vec<Attribute>, P<Bloc
     /// Precondition: already parsed the '{'.
     fn parse_block_tail(&mut self, lo: Span, s: BlockCheckMode) -> PResult<'a, P<Block>> {
         let mut stmts = vec![];
+        let mut recovered = false;
 
         while !self.eat(&token::CloseDelim(token::Brace)) {
             let stmt = match self.parse_full_stmt(false) {
                 Err(mut err) => {
                     err.emit();
-                    self.recover_stmt_(SemiColonMode::Ignore, BlockMode::Break);
+                    self.recover_stmt_(SemiColonMode::Ignore, BlockMode::Ignore);
                     self.eat(&token::CloseDelim(token::Brace));
+                    recovered = true;
                     break;
                 }
                 Ok(stmt) => stmt,
@@ -4397,12 +4399,13 @@ fn parse_block_tail(&mut self, lo: Span, s: BlockCheckMode) -> PResult<'a, P<Blo
             id: ast::DUMMY_NODE_ID,
             rules: s,
             span: lo.to(self.prev_span),
+            recovered,
         }))
     }
 
     /// Parse a statement, including the trailing semicolon.
     pub fn parse_full_stmt(&mut self, macro_legacy_warnings: bool) -> PResult<'a, Option<Stmt>> {
-        let mut stmt = match self.parse_stmt_(macro_legacy_warnings) {
+        let mut stmt = match self.parse_stmt_without_recovery(macro_legacy_warnings)? {
             Some(stmt) => stmt,
             None => return Ok(None),
         };