Fix dlsym() to take into account RTLD_GLOBAL/LOCAL

  Symbols from libraries opened with RTLD_LOCAL (default)
  should not be visible via dlsym(RLTD_DEFAULT/RTLD_NEXT, .)

Bug: 17512583
Change-Id: I1758943081a67cf3d49ba5808e061b8251a91964
diff --git a/tests/libs/dlopen_testlib_simple.cpp b/tests/libs/dlopen_testlib_simple.cpp
index bf750b2..3226955 100644
--- a/tests/libs/dlopen_testlib_simple.cpp
+++ b/tests/libs/dlopen_testlib_simple.cpp
@@ -19,6 +19,6 @@
 
 uint32_t dlopen_testlib_taxicab_number = 1729;
 
-bool dlopen_testlib_simple_func() {
+extern "C" bool dlopen_testlib_simple_func() {
   return true;
 }