The universal SDKROOT should only be assigned when hosted. Otherwise the SDKROOT can refer to the target when we're building for the host.
The universal SDKROOT should only be assigned when hosted. Otherwise the
SDKROOT can refer to the target when we're building for the host.

git-svn-id: a4a6f32337ebd29ad4763b423022f00f68d1c7b7@85672 91177308-0d34-0410-b5e6-96231b3b80d8

lodyagin/bare_cxx,lodyagin/bare_cxx,lodyagin/bare_cxx,lodyagin/bare_cxx,lodyagin/bare_cxx