[libFuzzer] Disable noasan-memcmp64.test and bcmp.test on Windows.

Summary: This patch disables (i) noasan-memcmp64.test on Windows as libFuzzer's interceptors are only supported on Linux for now, and (ii) bcmp.test as on Windows bcmp is not available in strings.h.

Reviewers: morehouse, hctim, kcc

Subscribers: #sanitizers

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D84536