rustdoc: add test case for masked blanket impl

Author: notriddle

src/test/rustdoc/auxiliary/masked.rs

@@ -8,3 +8,7 @@ pub trait MaskedTrait {
 impl MaskedTrait for String {
     fn masked_method() {}
 }
+
+pub trait MaskedBlanketTrait {}
+
+impl<T> MaskedBlanketTrait for T {}

src/test/rustdoc/masked.rs

@@ -10,6 +10,7 @@ extern crate masked;
 // @!hasraw 'search-index.js' 'masked_method'
 
 // @!hasraw 'foo/struct.String.html' 'MaskedTrait'
+// @!hasraw 'foo/struct.String.html' 'MaskedBlanketTrait'
 // @!hasraw 'foo/struct.String.html' 'masked_method'
 pub use std::string::String;