Merge pull request #2777 from xmcclure/win-makefile-aotcheck

Make `make fullaotcheck` in mono/mini runnable on Windows

Run with
MONO_EXECUTABLE=/path/to/msvc/mono.exe LIST_SEPARATOR=";"
This assumes you are running the test harness in Cygwin and you built mono with MSVC. Also, the test does not currently succeed.
Being able to run the test is a zeroth step toward making the test pass.