Binary Ninja: Improve flow analysis with correct xrefs, mark imported functions
Binary Ninja: Improve flow analysis with correct xrefs, mark imported functions

This addresses #99 (`TYPE_SWITCH` xrefs are backwards) and #100 (diverging
instructions not being treated as such).

The plugin now goes to great lengths to figure out code references and distinguish them
from data references ([BinaryNinja API issue 3559](https://github.com/Vector35/binaryninja-api/issues/3559)).

Note: I might refactor the plugin so that instead of decoding instructions one
by one, we rely on Binary Ninja's analysis and simply iterate over functions
their basic blocks.
PiperOrigin-RevId: 482437008
Change-Id: Ifb6f130dc35e1bb7df88db38ad3ea617d95b3aa8

google/binexport,google/binexport,google/binexport