GCC plugin support when using Ada

[PeteGarbett]

I see nothing in the GCC 4.5 release notes about 
plugin support being language specific, and yet if I using the treehydra
plugin with Ada (admittedly using a patched GCC 4.3.4 as per the dehydra
notes), I get this

gnat1: warning: command line option
"-fplugin=/home/linux/gcc-dehydra/dehydra/gcc_treehydra.so" is valid for
C/C++ but not for Ada

I assume the plan is to have something in the GCC 4 series be agnostic
about what front end has generated your GIMPLE. Is this correct?
I'd like to be able to analyse GIMPLE structures generated from gnat.