running 4.4 libstdc++ testsuite using 4.5's libstdc++ shared library

[Paolo Carlini]

Hi,

> running 4.4's libstdc++ testsuite using 4.5's libstdc++ shared library shows some additional test failures, compared to running 4.4 libstdc++ testsuite using the libstdc++ from the same build.
> 
> For two regressions found (running the binaries built with 4.4 on a system with 4.5's libstdc++ shared library) I filed PR44679 and PR44680, 

I will look into those later today, but frankly I don't understand the rationale of this kind of testing: if I fix a bug in 4.5, which is part of the code in the .so, and at the same time I adjust only the 4.5 testsuite to match, of course the 4.4 testsuite will show spurious regressions. And since we are not removing testcases from the testsuite, I don't see what genuine problems we are hoping to catch with that kind of obscure testing... Bah

Paolo.