Update the integration tests in preparation for Clang.

There's 2 way to pass some options to the SyzyAsan runtime:
- At instrumentation time by specifying them on the command line
  (e.g.: 'instrument.exe --mode=asan --asan-rtl-options="--foo --bar")
- At runtime via an environment variable (SYZYGY_ASAN_OPTIONS)

Only the environment variable approach works with Clang (yet, we might
consider making it possible to specify these options at instrumentation
time one day).

Most of the tests are failing with the Clang instrumented version of
the test DLL because they rely on the Asan options passed on the
command line at instrumentation time, there's no particular reason for
this except that it was cleaner than messing up with environment
variables. As we want to support Clang we'll need to switch to using
the env-var method.

Review-Url: https://codereview.chromium.org/2986323003
5 files changed