Built the 4.3 sources found at deb-src http://www.trinity.unimelb.edu.au/~dstone/xfree86/ ./ with gcc-3.3_3.3.1-0pre0 -O2 on i386. I'm unable to reproduce the recent miscompilation (still seeing this with the current soruces from unstable). Seems something is fixed in xfree86 or something isn't triggered anymore.
Please could you build this for the other architectures you reported the miscompilation? Thanks, Matthias