[C++] Embed precompiled bitcode in the gandiva library

[asfimport]

We were not running the pyarrow tests after installing the manylinux wheels, which can lead to uncaught issues, like: https://travis-ci.org/kszucs/crossbow/builds/484284104

Reporter: Krisztian Szucs / @kszucs
Assignee: Krisztian Szucs / @kszucs

Related issues:

• [C++][Gandiva] Compiled LLVM bitcode file path may result in libraries being non-relocatable (supercedes)

PRs and other links:

• GitHub Pull Request #3484

_{Note: This issue was originally created as ARROW-4372. Please see the migration documentation for further details.}

[asfimport]

Krisztian Szucs / @kszucs:
Issue resolved by pull request 3484
#3484