Optimize symbol lookup

 Do not run symbol lookup on already visited soinfos
 Not taking into account already visited libraries
 dramatically slows down dlsym in cases when there
 are multiple occurrences of a large library in
 dependency tree.

Bug: 16977077

(cherry picked from commit 042426ba6375f5c145379e598486ec6d675533c9)

Change-Id: I69d59e395e8112f119343e8a4d72fe31cd449f31
2 files changed