bpo-5755: remove compiler flag -Wstrict-prototypes

[jdemeyer]

https://bugs.python.org/issue5755

[jdemeyer]

CC @grimreaper

[grimreaper]

Strict Prototypes is correct and helpful for C. That said, the way it is currently implemented, by checking for the compiler in CC is sub-optimal at best.
CC ought to always be a C compiler, and never a C++ compiler.
It also seems questionable that distutils is using the python cflags rather than a dedicated set.

Please also remove OPT="$OPT $STRICT_PROTO" and any other reference to STRICT_PROTO since it is now unused.

TL;DR; +1 to this change; distutils should be fixed to not use python's CFLAGS; we should re-add strict-prototypes to CFLAGS when distutils is fixed.

[methane]

PR-7395 was merged, and backported to 3.7 and 3.6.