test_loadpaths_execute() was sometimes getting ERROR_ALREADY_EXISTS when creating its temporary directoryi. That was probably because GetTempFileNameW() only uses the low 16-bits of the 'random' LUID which goes over a wider range, potentially leading to collisions in the lower 16-bits. Avoid AllocateLocallyUniqueId() entirely and add a helper function to create a guaranteed new directory. Also try to use the current directory first as it is assumed to have been configured to ward off anti-virus programs (specifically Microsoft Defender) which is especially important when writing executables to that location. Only switch to the system's temporary directory if the current directory is not a writable location.
Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=54560 --- There are a few other tests where I suspect occasional anti-virus interference. It may make sense to reuse this function in those.
That said create_new_dir() uses entirely predictable sequenitial numbers which would be bad if attempting to create a secure directory. But the new directory does not even have special permissions and this type of attack shouldn't be an issue for the tests. Still, don't reuse this code in contexts where security matters.