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ARROW-3023: [C++] Add gold linker enabling logic from Apache Kudu

This will speed up builds some amount on systems with `ld.gold` available

Author: Wes McKinney <wesm+git@apache.org>

Closes #2405 from wesm/ARROW-3023 and squashes the following commits:

b33eeede <Wes McKinney> Add gold linker enabling logic from Apache Kudu