The code in question should be executed in all cases. This also fixes
palette refresh issues when shaders / paletted textures aren't around.

The current code doesn't work for this at all and causes major
rendering issues in e.g. C&C. I don't think we should fix this code
either since it isn't worth the effort and requires evil things like
paletteOverride.

This bug was originally introduced by
d4b63bbd, and then propagated by
1f029a30.

d3d8/tests: Clear with colors that are more obviously different from the expected value in test_rcp_rsq().

oledb32: Add tests for DBTYPE_I1/DBTYPE_UI1/DBTYPE_UI2/DBTYPE_UI4/DBTYPE_I8/DBTYPE_UI8 to DBTYPE_WSTR/DBTYPE_STR conversion.

Add an identical SkipVariance function to make the code clearer.