test: Enable extern-fn-reachable test

It didn't work because it tried to call itself but symbols are not
exported as default in executables.

Note that `fun5` is not internal anymore since it is in library.

src/test/run-make/extern-fn-reachable/Makefile

@@ -0,0 +1,6 @@
+-include ../tools.mk
+
+all:
+	$(RUSTC) dylib.rs -o $(TMPDIR)/libdylib.so
+	$(RUSTC) main.rs
+	$(call RUN,main)

src/test/run-make/extern-fn-reachable/dylib.rs

@@ -0,0 +1,24 @@
+// Copyright 2013-2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![crate_type = "dylib"]
+#![allow(dead_code)]
+
+#[no_mangle] pub extern "C" fn fun1() {}
+#[no_mangle] extern "C" fn fun2() {}
+
+mod foo {
+    #[no_mangle] pub extern "C" fn fun3() {}
+}
+pub mod bar {
+    #[no_mangle] pub extern "C" fn fun4() {}
+}
+
+#[no_mangle] pub fn fun5() {}

src/test/run-make/extern-fn-reachable/main.rs

@@ -8,32 +8,17 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// ignore-win32 dynamic_lib can read dllexported symbols only
-// ignore-linux apparently dlsym doesn't work on program symbols?
-// ignore-android apparently dlsym doesn't work on program symbols?
-// ignore-freebsd apparently dlsym doesn't work on program symbols?
-
 use std::unstable::dynamic_lib::DynamicLibrary;
-
-#[no_mangle] pub extern "C" fn fun1() {}
-#[no_mangle] extern "C" fn fun2() {}
-
-mod foo {
-    #[no_mangle] pub extern "C" fn fun3() {}
-}
-pub mod bar {
-    #[no_mangle] pub extern "C" fn fun4() {}
-}
-
-#[no_mangle] pub fn fun5() {}
+use std::os;
 
 pub fn main() {
     unsafe {
-        let a = DynamicLibrary::open(None).unwrap();
+        let path = Path::new("libdylib.so");
+        let a = DynamicLibrary::open(Some(&path)).unwrap();
         assert!(a.symbol::<int>("fun1").is_ok());
         assert!(a.symbol::<int>("fun2").is_err());
         assert!(a.symbol::<int>("fun3").is_err());
         assert!(a.symbol::<int>("fun4").is_ok());
-        assert!(a.symbol::<int>("fun5").is_err());
+        assert!(a.symbol::<int>("fun5").is_ok());
     }
 }