When second arch is translated we don't have 32-bit platform and
64-bit platform.  Instead we have two 32-bit ones, just one is
translated.

Test: Build system refactoring CL. Existing unit tests still pass.

BUG=31422117
BUG=27526885

Change-Id: Ia5fdd2f485dd5e4e8bc6799f0691cd03c2bff1a0
Reviewed-on: https://swiftshader-review.googlesource.com/8609Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Nicolas Capens <capn@google.com>
(cherry picked from commit f24b1b445274b0dbb4ffc860847a26d0b33d3a21)
Reviewed-on: https://swiftshader-review.googlesource.com/8611