Windows: Make CheckABICompatibility check a header dependent constant.
Windows: Make CheckABICompatibility check a header dependent constant.

Previously the check was for a standard installation of VisualStudio.
That check will have likely passed already, but the user could have
forced the include paths making the prior check somewhat meaningless.

Signed-off-by: Vassil Vassilev <0b291c0bdb4e22c8b7705ceedf8e168ff73f20e8@cern.ch>

karies/cling,root-mirror/cling,karies/cling,marsupial/cling,karies/cling,marsupial/cling,karies/cling,root-mirror/cling,karies/cling,root-mirror/cling,karies/cling,root-mirror/cling,marsupial/cling,marsupial/cling,root-mirror/cling,marsupial/cling,marsupial/cling,root-mirror/cling