Draft C2Y _BitInt related proposals

[Jakub Jelinek]

Hi!

As I wrote earlier, I'd like to see _BitInt I/O support in
*printf*/*scanf* and extending support of _BitInt in stdbit.h
in C2Y.

For those I wrote drafts of possible C2Y papers:
https://jakubjelinek.github.io/wg14/va_arg_bitint.html
https://jakubjelinek.github.io/wg14/stdbit_bitint.html

I'd appreciate any comments on this.
Haven't tried to acquire paper numbers for these yet.

	Jakub