API changes in std.json

[zjp-CN]

std.json is not based on the rust toolchain as upg targets, so this issue records the difference

std.json	upg mapping	memo
core::io::borrowed_buf::advance_unchecked core::io::borrowed_buf::set_init	advance_unchecked => advance set_init was removed	rust-lang/rust#148937 did the renaming and removal, but reverted them since rust-lang/rust#150096
core::intrinsics::drop_in_place		rust-lang/rust#140151 removes the fn
core::intrinsics::pref_align_of		rust-lang/rust#141803 removes the fn
std::collections::hash::map::get_many_unchecked_mut	get_many_unchecked_mut => get_disjoint_mut	rust-lang/rust#136152
core::any::downcast_{ref,mut}_unchecked	downcast_{ref,mut}unchecked => downcast_unchecked{ref,mut}	rust-lang/rust#148079
std::sys::pal::unix::process::process_common::pre_exec	std::sys::process::unix::common::pre_exec	rust-lang/rust#136929 change std::sys::pal::unix
core::intrinsics::min_align_of_val	min_align_of_val => align_of_val	rust-lang/rust#142410

Other changes on std.json:

• remove std::raw_attribute which is a Windows only fn and the path is not clear
• std::thread::spawn_unchecked => std::thread::builder::spawn_unchecked
• remove core::mem::maybe_uninit::slice_assume_init_{ref,mut} because they are now [MaybeUninit<T>]::assume_init+{ref,mut} stabilize maybe_uninit_slice rust-lang/rust#149102
• remove the unclear core::ptr::offset
• std::thread::from_raw => std::thread::thread::from_raw
• remove unclear std::from_raw_handle which is a Windows only fn
• some std::sys::pal::unix based path => std::sys::fs::unix ???
  • remove std::sys::anonymous_pipe::unix::from_raw_fd
  • remove std::sys::pal::unix::net::from_raw_fd
  • remove std::sys::pal::unix::fd::from_raw_fd
• remove core::intrinsics::copy::copy
• alloc::boxed::downcast_unchecked => alloc::boxed::downcast_unchecked
• sub_ptr => offset_from_unsigned, see Rename sub_ptr to offset_from_unsigned in docs rust-lang/rust#140391