win: Default to /SUBSYSTEM:CONSOLE
win: Default to /SUBSYSTEM:CONSOLE

This matches Chromium, and means that the entry point is main(), rather
than WinMain(), which is what standard gtest[_main] binaries expect.

BUG=crashpad:1
R=mark@chromium.org

Review URL: https://codereview.chromium.org/828783006

chromium/mini_chromium,bowlofstew/mini_chromium,chromium/mini_chromium,chromium/mini_chromium,bowlofstew/mini_chromium,Chilledheart/mini_chromium,Chilledheart/mini_chromium,bowlofstew/mini_chromium,Chilledheart/mini_chromium