Use the factory class in the FIRBuilder.
Add unit tests for the factory class function and the convert function
of the Complex class.
Reviewed By: clementval, rovka
Differential Revision: https://reviews.llvm.org/D114125
Co-authored-by: Jean Perier <jperier@nvidia.com>
Co-authored-by: Eric Schweitz <eschweitz@nvidia.com>
Kiran Chandramohan