While compiling xorg 6.8.2 with GCC 4.0 I discovered a couple of problems.

Here is the patch:
diff -ru -x '*.o' xorg-x11-6.8.2-r1/work/xc/programs/Xserver/cfb/cfbgc.c
/var/tmp/xorg-x11-6.8.2-r1/work/xc/programs/Xserver/cfb/cfbgc.c
--- xorg-x11-6.8.2-r1/work/xc/programs/Xserver/cfb/cfbgc.c      2005-03-10
13:33:16.000000000 -0700
+++ /var/tmp/xorg-x11-6.8.2-r1/work/xc/programs/Xserver/cfb/cfbgc.c    
2005-03-10 13:09:59.000000000 -0700
@@ -85,7 +85,7 @@
 # define usePolyGlyphBlt       miPolyGlyphBlt
 #endif

-void cfbUnPushPixels (GCPtr, PixmapPtr, DrawablePtr, int, int, int, int);
+static void cfbUnPushPixels (GCPtr, PixmapPtr, DrawablePtr, int, int, int, int);

 #ifdef FOUR_BIT_CODE
 # define usePushPixels cfbPushPixels8
diff -ru -x '*.o'
xorg-x11-6.8.2-r1/work/xc/programs/Xserver/hw/xfree86/drivers/ati/radeon_chipset.h
/var/tmp/xorg-x11-6.8.2-r1/work/xc/programs/Xserver/hw/xfree86/drivers/ati/radeon_chipset.h
---
xorg-x11-6.8.2-r1/work/xc/programs/Xserver/hw/xfree86/drivers/ati/radeon_chipset.h
2004-08-11 20:23:46.000000000 -0600
+++
/var/tmp/xorg-x11-6.8.2-r1/work/xc/programs/Xserver/hw/xfree86/drivers/ati/radeon_chipset.h
2005-03-10 13:27:06.000000000 -0700
@@ -1,4 +1,4 @@
-static SymTabRec RADEONChipsets[] = {
+SymTabRec RADEONChipsets[] = {
     { PCI_CHIP_RADEON_QD, "ATI Radeon QD (AGP)" },
     { PCI_CHIP_RADEON_QE, "ATI Radeon QE (AGP)" },
     { PCI_CHIP_RADEON_QF, "ATI Radeon QF (AGP)" },