Fixup for linkage on doctests

Summary:
We need to pass deps as immediate dependencies alongside the rlib when constructing linker args, so that we actually get the required `-lfoo` etc args on the link line.

Without this, we get undefined symbols when building doctests with `advanced_unstable_linking`.

Reviewed By: JakobDegen

Differential Revision: D61298029

fbshipit-source-id: 65594651e3f4716771b3e8d91bfd482fbd430222

prelude/rust/build.bzl

@@ -350,7 +350,7 @@ def generate_rustdoc_test(
                     link_infos,
                     deps = inherited_merged_link_infos(ctx, doc_dep_ctx),
                     preferred_linkage = Linkage("static"),
-                )],
+                )] + inherited_merged_link_infos(ctx, doc_dep_ctx),
                 params.dep_link_strategy,
             ),
         ],