After testing, I think I like '-fp-model strict' better in CFLAGS_NODIST.  On Ubuntu, `CC=gcc ./python -m test.test_distutils` passes when the flag is in CFLAGS_NODIST, but fails when it's in BASECFLAGS.  On OSX, it fails both ways, due to deployment target issues; I suspect that's probably solvable by setting some other environment variable correctly (I don't know enough about OSX to say for sure, though).  I don't think this patch needs to go as far as the LTO patch does to add the argument to CFLAGS; most third party extensions probably won't necessitate '-fp-model strict', those that do can add it themselves.

On the other hand, 2.7 doesn't have CFLAGS_NODIST (and I don't want to add it), so BASECFLAGS is about the only option there.

Barring objections, I'll commit this new patch in a few days.