Auto-generate testlist.c files

Wine tests use testlist.c files that simply provide declarations and table entries for each test file.
Example: https://github.com/reactos/reactos/blob/master/modules/rostests/winetests/advapi32/testlist.c

We currently have the Wine build process generate these files, then check them into Git. It would be nicer to have our build process generate them as well.
This would definitely make sense for Wine tests, but may even be extended to other Wine-style tests such as APITests and KMTests.