[compiler-rt] [asan] Pass -falign-functions=16 when building on Windows (PR #154694)

[Hans Wennborg via llvm-commits]

zmodem wrote:

> This will only work if the function following `__asan_on_error` is aligned to 16, so this doesn't really guarantee anything either.

I think it would work in practice, but `/hotpatch` seems like a better way to express what we actually want, so let's use that.

https://github.com/llvm/llvm-project/pull/154694