improving testing scheme (was Re: ACATS and GCC testsuite)

[Richard Kenner]

    "make check" could look at the configuration in the build directory to
    find out where the compiler should have been installed, and look there
    rather than in $PATH.

Sure, but the problem there is that it has no way to know if the install
actually *was* done, leaving the risk of somebody doing a make, then a
make check, forgetting to do the make install, and thinking they tested
their changes when they actually didn't.