- Add ptr::non_null::NonNull / ffi::c_str::CStr / ffi::c_str::CString
  intermediate-module variants so those methods resolve under their
  rustc_public fully-qualified names (which include the module).
- Only report intrinsics missing from crates that were actually loaded,
  so verifying core no longer floods warnings for alloc/std-only
  functions (dealloc, Vec::push, Box::from_raw, ...).
- Gate box_assume_init_into_vec_unsafe on rapx_ge_100 (the vec! helper it
  names only exists in rustc 1.100's const_heap).
- Keep slice_into_vec registered under std::slice/core::slice, matching
  def_path_str's facade-crate resolution (not alloc::slice).