Fix mismatch between cc and python for windows prefer32

Windows prefer32 was implemented in cc, which caused a mismatch
between cc and other packages like python.  This manifested as
missing variant when a python_test_host with compile_multilib: "first"
tried to depend on a cc_binary_host, which implicitly has multilib
"first".

Fixes: 177904375
Test: m checkbuild
Change-Id: Iaaac16ae171c06d90d04d7cac11789d3f39b8d99