Compile in 32-bit

Summary:
Explicitly add -m32 and -m elf_i386 for gcc/ld to generate 32-bit
code, otherwise multilib gcc's default 64-bit can break the build

Change-Id: I1011f5dc60e27403fdd42e80168dc8c48af04082

Test Plan: TBA

Reviewers: Mustaavalkosta, randall.rushing, rlasalle15, Roach

Differential Revision: http://review.codefirex.com/D218