This fixes CORE-15708 "PdfSam 3.3.5 setup can not decode bmp"
https://jira.reactos.org/browse/CORE-15708
Wine does not have this issue, but it did not have it back when last sync to
WineStaging-4.18 was done. This commit is as near as possible to actual
wine-7.0-rc3 version. This wine code uses reverse_bgr8 instead of own
convert_rgba_to_bgra, but it leads to wrong colors.