qt.x86.cflags.diff.gz NOT this makes qt only compiled
on x86!!
The SlackBuild I posted (and also the SlackBuild from Slackware
12.2/13.0) does apply this patch only if $ARCH is equal to i486.
The only goal of this patch is (was?) to enforce the -march and -mtune
defaults of Slackware, but I'm not sure of it being useful anymore
since CFLAGS/CXXFLAGS are passed to ./configure in the build script.
Anyway, it is pure Slackware policy.