[ASan/Win] Fix issue 305 -- don't instrument .CRT initializer/terminator callbacks

See https://code.google.com/p/address-sanitizer/issues/detail?id=305
Reviewed at http://reviews.llvm.org/D3607

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207968 91177308-0d34-0410-b5e6-96231b3b80d8