[bazel] Fix build on Windows.

Signed-off-by: Piotr Sikora <piotrsikora@google.com>
Change-Id: I25ed38cc61cb3b621a71c4fe9e3b7cfb0e7578ba
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3368871Reviewed-by: Victor Gomes <victorgomes@chromium.org>
Commit-Queue: Victor Gomes <victorgomes@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78509}

bazel/defs.bzl

@@ -367,6 +367,7 @@ def _v8_target_cpu_transition_impl(settings, attr):
         "x86_64": "x64",
         "darwin": "x64",
         "darwin_x86_64": "x64",
+        "x64_windows": "x64",
         "x86": "ia32",
         "ppc": "ppc64",
         "arm64-v8a": "arm64",