Where are XF86VidModeQueryVersion and XF86VidModeGetModeLine?

[hendrik@topoi.pooq.com]

I hace compiled a program many times on an a386 etch system using the 
command:

gcc -g -L/usr/lib/ -lglut -lGLU -lGL -ljpeg rj.c jp.c -o i686/jp

Now, however, I am compiling it on an AMD64 machine, also running etch.  
The command I used is  

gcc -g -L/usr/lib/ -lglut -lGLU -lGL -ljpeg rj.c jp.c -o x86_64/jp

Much the same, except I use an architecture-specific directory for my 
architecture-specific object file.

But on AND-64 I get 

gcc -g -L/usr/lib/ -lglut -lGLU -lGL -ljpeg rj.c jp.c -o x86_64/jp
/usr/lib//libGL.a(glxcmds.o): In function `glXGetMscRateOML':
(.text+0x2da1): undefined reference to `XF86VidModeQueryVersion'
/usr/lib//libGL.a(glxcmds.o): In function `glXGetMscRateOML':
(.text+0x2dd4): undefined reference to `XF86VidModeGetModeLine'
collect2: ld returned 1 exit status
make: *** [x86_64/jp] Error 1
hendrik@april:~/dv/im$

Now presumably this means that some library is missing.  Or contains 
maverick references to XF86 code (my systems both run xorg, and have not 
been promoted to xorg 7.0 yet.)  I'm not sure the problem is 
AMD-64-specific; I might well have accidentally done something weird in 
the course of history.

What's missing?  Or is one of the libraries defective on AMD64?

-- hendrik