Make dt_runpath work for libraries opened from apk

This patch also fixes realpath for libraries opened directly
from apks.

Bug: http://b/21960914
Bug: http://b/21961857
Change-Id: I35ade661c87f1d448191f385811f6e9fd3cacf11
diff --git a/tests/libs/dlopen_b.cpp b/tests/libs/dlopen_b.cpp
index 5291d81..cd81e16 100644
--- a/tests/libs/dlopen_b.cpp
+++ b/tests/libs/dlopen_b.cpp
@@ -4,8 +4,9 @@
   // remove once it is fixed
   static int dummy = 0;
 
-  // This is not supposed to succeed. Even though this library has DT_RUNPATH
-  // for libtest_dt_runpath_x.so, it is not taked into account for dlopen.
+  // This is supposed to succeed because this library has DT_RUNPATH
+  // for libtest_dt_runpath_x.so which should be taken into account
+  // by dlopen.
   void *handle = dlopen("libtest_dt_runpath_x.so", RTLD_NOW);
   if (handle != nullptr) {
     dummy++;