## Summary
Compiler Targets can carry device-type semantics that runtime
device-name parsing does not preserve.
- add `tvm.device_from_target` for canonical Target-to-Device
translation
- use explicit runtime constructors where the device kind is fixed
- update target-derived utilities, tests, and documentation to use the
explicit boundary
This PR cleans up the python API to make things more consistent
with existing python array api and torch.
Device update
- device_id => index, to be consistent with torch
- device_type => dlpack_device_type() returns int
- added type property same as torch.device
API updates:
- Move the convenient method like cpu() out into tvm runtime to keep device minimal
- tvm_ffi._init_api => tvm_ffi.init_ffi_api
- tvm_ffi.register_func => tvm_ffi.register_global_func
* Add Python representation for VirtualDevice
This adds a Python class to represent the VirtualDevice so that the
behaviour for `device_type()` can be semi-replicated.
These tests were actually not being ran and were broken so I've added
them to the integration script.
* Update other references to make_virtual_device
Tianqi Chen