Implement lookup by DT_SONAME

  This CL also fixes SEARCH_NAME hack and resolves
  https://code.google.com/p/android/issues/detail?id=6670
  once and for all.

Bug: https://code.google.com/p/android/issues/detail?id=6670
Change-Id: I9b8d6a672cd722f30fbfbb40cdee8d9b39cfe56e
diff --git a/linker/dlfcn.cpp b/linker/dlfcn.cpp
index 9a8dbc9..64df7a5 100644
--- a/linker/dlfcn.cpp
+++ b/linker/dlfcn.cpp
@@ -248,6 +248,7 @@
     __libdl_info.ref_count_ = 1;
     __libdl_info.strtab_size_ = sizeof(ANDROID_LIBDL_STRTAB);
     __libdl_info.local_group_root_ = &__libdl_info;
+    __libdl_info.soname_ = "libdl.so";
   }
 
   return &__libdl_info;