Show summary lines on cross-crate re-exports

This removes the unnecessary `DocFragmentKind::Divider` in favor of just
using the logic I actually want in `collapse_docs`.

src/test/rustdoc/auxiliary/intra-link-reexport-additional-docs.rs

@@ -0,0 +1,6 @@
+#![crate_name = "inner"]
+
+/// Links to [f()]
+pub struct Inner;
+
+pub fn f() {}

src/test/rustdoc/auxiliary/reexport-check.rs

@@ -0,0 +1,2 @@
+/// Docs in original
+pub struct S;

src/test/rustdoc/intra-link-reexport-additional-docs.rs

@@ -1,6 +1,9 @@
+// aux-build:intra-link-reexport-additional-docs.rs
+// build-aux-docs
 #![crate_name = "foo"]
+extern crate inner;
 
-// @has foo/struct.JoinPathsError.html '//a[@href="../foo/fn.with_code.html"]' 'crate::with_code'
+// @has foo/struct.Inner.html '//a[@href="../foo/fn.with_code.html"]' 'crate::with_code'
 /// [crate::with_code]
 // @has - '//a[@href="../foo/fn.with_code.html"]' 'different text'
 /// [different text][with_code]
@@ -11,7 +14,9 @@
 #[doc = "has an attr in the way"]
 ///
 /// [reference link]: me_three
-pub use std::env::JoinPathsError;
+// Should still resolve links from the original module in that scope
+// @has - '//a[@href="../inner/fn.f.html"]' 'f()'
+pub use inner::Inner;
 
 pub fn with_code() {}
 pub fn me_too() {}

src/test/rustdoc/reexport-check.rs

@@ -1,5 +1,8 @@
+// aux-build:reexport-check.rs
 #![crate_name = "foo"]
 
+extern crate reexport_check;
+
 // @!has 'foo/index.html' '//code' 'pub use self::i32;'
 // @has 'foo/index.html' '//tr[@class="module-item"]' 'i32'
 // @has 'foo/i32/index.html'
@@ -7,3 +10,8 @@ pub use std::i32;
 // @!has 'foo/index.html' '//code' 'pub use self::string::String;'
 // @has 'foo/index.html' '//tr[@class="module-item"]' 'String'
 pub use std::string::String;
+
+// @has 'foo/index.html' '//td[@class="docblock-short"]' 'Docs in original'
+// this is a no-op, but shows what happens if there's an attribute that isn't a doc-comment
+#[doc(inline)]
+pub use reexport_check::S;