Experiments show xcopy under Windows does not use argc/argv logic for
treating double quotes and backslashes. The xcopy logic is simplified
because literal quotes are illegal in Windows file names, thus escaped
double quotes (\") need not be treated.  'XCOPY "c:\dir a" "c:\dir
b\"' works under Windows.

Translation by Đorđe Vasiljević.

Instead of directly from the stateblock. Note that the GLSL backend doesn't
take these flags into account at all. That's probably a bug in the GLSL
backend, but needs tests.