[asan] Fix Windows global dead stripping tests

Pass /Gw to clang-cl which is equivalent to -fdata-sections. This is now
necessary.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@301272 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed