I can confirm that backing out the above patch and rebuilding the package makes GNOME work again on my PowerPC G3.
Please re-open this bug.
The "open" bit of this bug refers to the need to figure out why Altivec detection is broken, so that it can be re-enabled without breaking G3s. Ubuntu's problem is that Altivec detection has somehow been re-enabled, and is still broken. It doesn't appear to me that Debian has this problem.
I can confirm that backing out the above patch and rebuilding the package makes GNOME work again on my PowerPC G3.
Please re-open this bug.
The "open" bit of this bug refers to the need to figure out why Altivec detection is broken, so that it can be re-enabled without breaking G3s. Ubuntu's problem is that Altivec detection has somehow been re-enabled, and is still broken. It doesn't appear to me that Debian has this problem.
(just trying to be clear)