Move inlinability determination into cache transform (#57979)
Currently the inlineability determination is in a bit of an odd spot -
just after the optimizers while everything is still in IRCode. It seems
more sensible to move this code into the cache transformation code,
which is the first place that makes an actual decision based on
inlineability. If an external AbstractInterpreter does not need to
covert to CodeInfo for compilation purposes this also potentially saves
that extra conversion. While we're at it, clean up some naming to
deconflict it with other uses.
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Co-authored-by: Cédric Belmant <cedric.belmant@juliahub.com>
