Fix go/ab builds for jb-mr1

Fix go/ab builds for jb-mr1

This forces clang to avoid use init_array for all initialization rather than
splitting the initialization between init_array and ctors.

Local builds do this anyway, but for some reason the builds on go/ab do not.
Setting this flag makes the builds consistent (and unbroken on JB-MR1).

I already checked this in on cloud-android-current-release because I wanted
to test it before submitting.

Bug 25597090

Change-Id: I5a7195ba53531835fb8333b698ed39d21ff847a6
(cherry picked from commit 95c7182f118cc686df27c3f49db7d3c7908e0e59)
Reviewed-on: https://swiftshader-review.googlesource.com/4271
Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Greg Hartman <ghartman@google.com>