sending of headers to output stream and flushing the internal headers buffer.
Patch contribution by Andrew Schaaf

Issue #11188: In log2 tests, create powers of 2 using ldexp(1, n) instead of the less reliable 2.0**n.

pthread_t is a pointer, not an integer, on FreeBSD. It should fix the following
gcc warning:

passing argument 1 of ‘pthread_kill’ makes pointer from integer without a cast

I expect the system libc to use more accurate functions than Python. The GNU
libc uses for example FYL2X and FYL2XP1 hardware instructions on Intel FPU.

Patch by Arfrever Frehtes Taifersar Arahesis.

Patch by Arfrever Frehtes Taifersar Arahesis.

#11910: change import_fresh_module to return None when one of the "fresh" modules can not be imported.

Dickinson.