Build host tools as 32bit on all Darwin machines.
Build host tools as 32bit on all Darwin machines.

Change-Id: I121b388056e68b787518c66a01c172bc4ffaef9b

xorware/android_build,Hybrid-Power/startsync,RR-msm7x30/platform_manifest,fallouttester/platform_manifest,xorware/android_build,xorware/android_build,xorware/android_build,hagar006/platform_manifest,xorware/android_build,pranav01/platform_manifest,ND-3500/platform_manifest,knone1/platform_manifest,see4ri/lolili