Switch from old-style ASSERT macro to new-style ASSERT_EQ,... macros.
Using new-style macros makes it easier to debug test failures
Fixes: https://github.com/libuv/libuv/issues/2974
Reading and writing files using a memory file mapping can be
significantly faster on Windows.
PR-URL: https://github.com/libuv/libuv/pull/2295
Reviewed-By: Bartosz Sosnowski <bartosz@janeasystems.com>