configure: Define WINE_CROSSTEST when building crosstests, and disable use of config.h in that case.

dbghelp: When trying to enumerate locals & parameters with SymEnumSymbols, don't return a global or public symbol when the nearest symbol of the current context isn't a function.

Otherwise the vertex shader will see stale posFixup values.

It's unused, all states that have this as handler have a 0 representative.

wined3d: Only apply float R16G16F/R32G32F fixup when ARB_texture_rg isn't around and remove redundant code.

wined3d: Remove redundant gl format/type code from d3dfmt_get_conv since it is already in the table.