Add test for module ambiguity

Author: Manishearth

src/test/rustdoc/intra-doc-link-mod-ambiguity.rs

@@ -0,0 +1,18 @@
+// ignore-tidy-linelength
+
+#![deny(intra_doc_link_resolution_failure)]
+
+
+pub fn foo() {
+
+}
+
+pub mod foo {}
+// @has intra_doc_link_mod_ambiguity/struct.A.html '//a/@href' '../intra_doc_link_mod_ambiguity/foo/index.html'
+/// Module is [`module@foo`]
+pub struct A;
+
+
+// @has intra_doc_link_mod_ambiguity/struct.B.html '//a/@href' '../intra_doc_link_mod_ambiguity/fn.foo.html'
+/// Function is [`fn@foo`]
+pub struct B;