Add more io_uring ZCRX definitions

[silvanshade]

Related: bytecodealliance/rustix#1485

Submitting this as a draft until the rustix and rustix-uring PRs are ready.

Note that I changed IORING_ZCRX_AREA_SHIFT to a u64. I believe this is how it should be judging from its use in liburing for setting the rqe offset and for computing IORING_ZCRX_AREA_MASK.

CC @LtdJorge

[silvanshade]

@sunfishcode I think this should be ready for review now. There might be some additional changes needed here to enable zcrx (see my comment) but I can't actually test that right now anyway.

[sunfishcode]

These are auto-generated source files. If you wish to change the type of IORING_ZCRX_AREA_SHIFT etc., please change the C code in gen/modules/io_uring.h to redefine them to something that bindgen will infer the desired types from.

[sunfishcode]

Similarly, to add new macros that bindgen itself doesn't pick up, please add the definitions to gen/modules/io_uring.h so that bindgen does pick them up.