Moving to new style test macros will make debugging easier in case
of test failure and improve redability. This commit will replace all
ASSERT macros matching the statement:
`ASSERT(identifier (== or !=) value);`
to:
`ASSERT_(NOT_)NULL(identifier);`
Refs: https://github.com/libuv/libuv/issues/2974
PR-URL: https://github.com/libuv/libuv/pull/3081
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>
