[VM/C-API] - Fix errors reported by MSVC tool chain.
[VM/C-API] - Fix errors reported by MSVC tool chain.

For details see https://logs.chromium.org/logs/flutter/buildbucket/cr-buildbucket.appspot.com/8873403898611684880/+/steps/build_android_profile_gen_snapshot/0/stdout

Change-Id: I47fe33cab787595dff13b68c613fb216fb434f3b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/157560
Reviewed-by: Alexander Aprelev <dfb74c35a357c2059971a4bf7fe26b6a7c18085d@google.com>
Commit-Queue: Siva Annamalai <2e618a8cbd7bb6b3d4409061ae407d692a098546@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk