[patch 4/4] -fstrict-volatile-bitfields cleanup v3: remove from defaults on all targets

[DJ Delorie]

> How about this for a compromise: Let's make the default of
> -fstrict-volatile-bitfields an optional configure argument for gcc
> 4.9, that can be used for every target, even for X86_64 of you want ?

I don't care how it's enabled (currently, each target that wants it,
sets it) as long as a plain "./configure" gives the correct defaults.
"Don't forget this option or your code won't work" isn't an option.