rustdoc: do not strip blanket impls in crate of origin

In `impl<T> Trait for T`, the blanket type parameters `T` were
recognized as "local" and "not exported", so these impls were
thrown out.

Now we check if they are generic, and keep them in that case.

Fixes: #29503

1 files changed, 7 insertions, 0 deletions

diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index f5b8db1143e..a47b66bf2f7 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -1540,6 +1540,13 @@ impl Type {
             _ => None,
         }
     }
+
+    pub fn is_generic(&self) -> bool {
+        match *self {
+            ResolvedPath { is_generic, .. } => is_generic,
+            _ => false,
+        }
+    }
 }
 
 impl GetDefId for Type {