Auto merge of #28534 - marcusklaas:fix-mod-inner-span, r=alexcrichton

Fixes https://github.com/rust-lang/rust/issues/28520.

r? @alexcrichton or @nrc?

src/libsyntax/parse/parser.rs

@@ -4843,7 +4843,7 @@ impl<'a> Parser<'a> {
         let hi = if self.span == codemap::DUMMY_SP {
             inner_lo
         } else {
-            self.span.lo
+            self.last_span.hi
         };
 
         Ok(ast::Mod {