make anything used in a resource body always reachable

(they appear to be uncond. inlined)

Fixes #2170.

src/rustc/middle/trans/reachable.rs

@@ -84,7 +84,11 @@ fn traverse_public_item(cx: ctx, item: @item) {
               for vec::each(nm.items) {|item| cx.rmap.insert(item.id, ()); }
           }
       }
-      item_res(_, tps, blk, _, _) | item_fn(_, tps, blk) {
+      item_res(_, tps, blk, _, _) {
+        // resources seem to be unconditionally inlined
+        traverse_inline_body(cx, blk);
+      }
+      item_fn(_, tps, blk) {
         if tps.len() > 0u ||
            attr::find_inline_attr(item.attrs) != attr::ia_none {
             traverse_inline_body(cx, blk);

src/test/auxiliary/issue2170lib.rs

@@ -0,0 +1,8 @@
+export rsrc;
+
+fn foo(_x: i32) {
+}
+
+resource rsrc(x: i32) {
+    foo(x);
+}

src/test/run-pass/issue2170exe.rs

@@ -0,0 +1,7 @@
+// xfail-fast - check-fail fast doesn't under aux-build
+// aux-build:issue2170lib.rs
+use issue2170lib;
+
+fn main() {
+    let _ = issue2170lib::rsrc(2i32);
+}