This also improves GetProcAddress performance by using binary search
instead of linear search.

Fixes bug b/20110899

Change-Id: I6c58e17f0580904338e4d806e310cccbec398f28
Reviewed-on: https://swiftshader-review.googlesource.com/15748Tested-by: Krzysztof Kosiński <krzysio@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>