Constrain asan_rtl to XP-ony import libs for kernel32.dll and user32.dll.
Constrain asan_rtl to XP-ony import libs for kernel32.dll and user32.dll.

This works as-is, and is a big improvement on the current situation.
However, asan_rtl has a bunch of additional imports that apparently are
satisifed through #pragma comment(link, ...). It would be better to
generate all the needed import libs, and to ignore all default
imports, instead of only the kernel32 and user32 ones.

R=chrisha@chromium.org

Review URL: https://codereview.appspot.com/9836044

git-svn-id: db59699583a60be9a535cd09cdc9132301867226@1551 15e8cca8-e42c-11de-a347-f34a4f72eb7d

sebmarchand/syzygy,google/syzygy,sebmarchand/syzygy,ericmckean/syzygy,wangming28/syzygy,sebmarchand/syzygy,pombreda/syzygy,ericmckean/syzygy,pombreda/syzygy,wangming28/syzygy,wangming28/syzygy,supriyantomaftuh/syzygy,supriyantomaftuh/syzygy,ericmckean/syzygy,google/syzygy,pombreda/syzygy,ericmckean/syzygy,wangming28/syzygy,sebmarchand/syzygy,google/syzygy,pombreda/syzygy,sebmarchand/syzygy,supriyantomaftuh/syzygy,supriyantomaftuh/syzygy,google/syzygy,pombreda/syzygy,Eloston/syzygy,ericmckean/syzygy,Eloston/syzygy