bdist_wheel should be able to work with pre-computed dist-info, per PEP-517

[pelson]

As discussed at pypa/setuptools#1825, PEP-517 states that a wheel building backend should be able to accept an existing dist-info directory.

If the build frontend has previously called prepare_metadata_for_build_wheel and depends on the wheel resulting from this call to have metadata matching this earlier call, then it should provide the path to the created .dist-info directory as the metadata_directory argument. If this argument is provided, then build_wheel MUST produce a wheel with identical metadata. The directory passed in by the build frontend MUST be identical to the directory created by prepare_metadata_for_build_wheel, including any unrecognized files it created.

Currently, bdist_wheel does not make this possible. Would it be possible to add a dist-info-dir or equivalent argument to bdist_wheel?