[patch] Fix problematic debug info for parameters at -O0

[Eric Botcazou]

> The testcase doesn't necessarily need to FAIL without the patch on x86, it
> is fine if it fails on some PowerPC* or Visium.

Well, the value of a guality test that isn't exercised on x86 is close to 0, 
but I can try on PowerPC indeed.

-- 
Eric Botcazou