Today, test_RtlUniform() skips almost all of its tests on Windows Vista or later. The skipped tests only succeed in Windows XP, and fail on Windows Vista or later.
This is because RtlUniform()'s behavior has changed, presumably due to a bug fix shipped in Windows Vista. It appears that RtlUniform, a linear congruential generator, could overflow before computing the modulo in WindoWs XP. This is no longer the case in Windows Vista or later.
Meanwhile, we no longer support Windows XP behavior and thus do not test for it regularly; therefore, the tests are obsolete as of 2023.
Remove obsolete tests that no longer work with any of the Windows versions actively tested by WineHQ (as of 2023), and replace them with updated tests that works in the Windows versions from Vista up to 10.
Also, fix Wine's RtlUniform() to match the new behavior accordingly.
-- v8: ntdll: Fix integer overflow in RtlUniform.