Assumes that (is_clang = false && !is_win) => GCC or other compiler with
inline assembly that is gas-compatible.

Bug: chromium:1056170
Change-Id: I1a2a2d13b7d4af630349d9194b64394c9736ad3c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2137405Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67014}