Fix more misspelled comments and strings.

src/libsyntax/parse/parser.rs

@@ -2582,7 +2582,7 @@ pub fn parse_loop_expr(&mut self, opt_ident: Option<ast::Ident>) -> @Expr {
         self.mk_expr(lo, hi, ExprLoop(body, opt_ident))
     }
 
-    // For distingishing between struct literals and blocks
+    // For distinguishing between struct literals and blocks
     fn looking_at_struct_literal(&mut self) -> bool {
         self.token == token::LBRACE &&
         ((self.look_ahead(1, |t| token::is_plain_ident(t)) &&